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Magnetic Materials (magnetic + material)

Distribution by Scientific Domains

Polymers and Materials Science	21%
Physics and Astronomy	21%
Chemistry	21%
Engineering	17%
Medical Sciences	7%

Kinds of Magnetic Materials

soft magnetic material

Selected Abstracts

Synthesis and Characteristics of a Phase-Change Magnetic Material,

ADVANCED MATERIALS, Issue 12 2008
Wen-Dong Song
A phase-change magnetic material is synthesized by doping the known GeSbTe phase-change material with Fe, and its properties are compared with the parent chalcogenide material (see figure). Besides different optical (reflectivity) and electrical properties in the amorphous and crystalline states, its magnetic properties are different in the two states; a fact that can be used to realize the fast control of ferromagnetism by phase change. [source]

Hybrid Magnetic Materials Based on Nitroxide Free Radicals and Extended Oxalato-Bridged Bimetallic Networks

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 2 2005
Antonio Alberola
Abstract A series of hybrid organic-inorganic magnets of formula p -rad[MIICr(ox)3] [M = Mn (1), Co (2), Ni (3), Zn (4)] and m -rad[MIICr(ox)3] [M = Mn (5), Co (6)], in which N -methylpyridinium cations bearing a nitronyl nitroxide moiety in positions 3 (m -rad) or 4 (p -rad) of the pyridine ring coexist with the 2D honeycomb-like oxalato-bridged bimetallic lattice, has been prepared and studied by AC and DC magnetic susceptibility measurements and EPR spectroscopy. In general, the physical properties of these magnets are not altered significantly by the insertion of the nitronyl nitroxide radicals although these paramagnetic molecules seem to interact weakly with the inorganic network as demonstrated by EPR spectroscopy. Some differences can also be observed between the p -rad and m -rad series, i.e. m -rad derivatives have smaller values for the critical temperatures and coercive fields. We also report on the X-ray crystal structures and magnetic properties of p -rad[Mn(H2O)Cr(ox)3]·2H2O (7) and m -rad[Mn(H2O)2Cr(ox)3]·2H2O (8), two extended oxalato-bridged compounds with new topologies. Compound 7 is antiferromagnetic and its structure is a 3D achiral lattice in which zigzag ferromagnetic MnCr chains (J/k = +0.8 K) are interconnected to form hellicoidal hexagonal channels with the cationic free radicals residing in the free space. Compound 8, however, exhibits a ladder-like structural pattern with competing magnetic interactions and paramagnetic behaviour down to low temperatures. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

Magnetic Materials: X-Ray Magnetic Circular Dichroism Picks out Single-Molecule Magnets Suitable for Nanodevices (Adv. Mater.

ADVANCED MATERIALS, Issue 2 2009
2/2009)
The surface sensitivity of X-ray magnetic circular dichroism in extreme conditions has been exploited to investigate the first layers of bulk single-molecule magnets (SMMs), as reported by Roberta Sessoli and co-workers on p. 167. Striking differences have emerged between two classes of SMM having different structural constraints, thus highlighting the importance of molecular design in the realization of molecular spintronic devices. [source]

Dual Chromophore-Nitroxides: Novel Molecular Probes, Photochemical and Photophysical Models and Magnetic Materials

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2007
Gertz I. Likhtenstein
Over the last decades scientists have faced growing requirements in novel methods of fast and sensitive analysis of antioxidant status of biological systems, spin redox probing and spin trapping, investigation of molecular dynamics, and of convenient models for studies of photophysical and photochemical processes. In approaching this problem, methods based upon the use of dual chromophore-nitroxide (CN) compounds have been suggested and developed. A CN consists of two molecular sub-functionality (a chromophore and a stable nitroxide radical) tethered together by spacers. In the dual compound the nitroxide is a strong intramolecular quencher of the fluorescence from the chromophore fragment. Reduction to hydroxylamine, oxidation of the nitroxide fragment or addition of an active radical yield the fluorescence increase and the parallel decay of the fragment electron spin resonance (ESR) signal. At certain conditions the dual molecules undergo photomagnetic switching and form excited state multi-spin systems. These unique properties of CN were intensively exploited as the basis for several methodologies, which include molecular probing, modeling intramolecular photochemical and photophysical processes, and construction of new magnetic materials. [source]

Geophysical exploration of Guajará, a prehistoric earth mound in Brazil

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2003
Bruce W. Bevan
An interdisciplinary team studied Guajará, a prehistoric artificial mound in the Brazilian Amazon. The geophysical surveys and excavations were interactive;this interaction furnished more information than either geophysics or excavation alone could have provided. While seven different geophysical methods were applied, the magnetic survey reported here was particularly valuable. A detailed interpretation of this survey quantified the magnetic material in the mound, and this furnished an initial estimate of the number of cooking hearths in the mound. Ten test excavations were concentrated at magnetic anomalies. These excavations located cooking hearths and burial urns. A reevaluation of the magnetic survey was then done in order to refine the estimate of the number of hearths in the mound; this yielded an estimate of 2200 hearths. This allowed the population of the site to be approximated at 78,156 people. The geophysical survey and excavations also identified possible locations for subsequent broad-area excavations. © 2003 Wiley Periodicals, Inc. [source]

Synthesis and Characteristics of a Phase-Change Magnetic Material,

Light FCC gasoline olefin oligomerization over a magnetic NiSo4/,-Al2o3 catalyst in a magnetically stabilized bed

AICHE JOURNAL, Issue 3 2009
Ying Peng
Abstract Magnetic NiSO4/,-Al2O3 catalysts were prepared by impregnating NiSO4 solutions onto the ,-Al2O3 support containing a magnetic material of Fe3O4. Characterization by XRD, NH3 -TPD, and thermal analysis showed that the magnetic NiSO4/,-Al2O3 catalyst with a nickel content of 7.0% by weight had a monolayer dispersion of NiSO4 and the largest number of moderate strength acid sites, and a high specific saturation magnetization. The magnetic catalyst was evaluated for light FCC gasoline olefin oligomerization in both fixed-bed and magnetically stabilized bed (MSB) reactors. Comparing with that in the fixed-bed reactor, the optimal reaction temperature in the MSB lowered to 443 K, and its space velocity ranged broadly from 2.0 to 6.0 h,1. The sulfur-free diesel distillate produced by operation of the MSB for 100 h had higher cetane number and good low-temperature flow property, which illuminates a promising application of the MSB to manufacture clean diesel fuels with high productivity and flexibility. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

Dual-band patch antenna on magnetic substrate for WLAN communication

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2007
Wang Encheng
Abstract This article introduces a novel dual-band patch antenna printed on organic magnetic substrate for WLAN communication, operating at 2.45 and 5 GHz. The dual-band operation is obtained through embedding a pair of L-shaped slots. The antenna has smaller size for the use of magnetic material, compared with rectangular microstrip antennas on normal dielectric substrate. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1445,1447, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22405 [source]

Measurement of AC current using an optical fibre sensor

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2007
C. H. Cheng
Abstract In the power industry, current is measured for metering and protection purposes. For said measurement, we demonstrated an optical fibre sensor using a single Fibre Bragg Grating (FBG) for measuring AC current for this paper. The sensor head is based on an FBG encased in a polymer-half-field metal cylinder, embedded in a magnetic material at the measuring point with the characteristics of an all-optical high pressure sensitivity. The operating mechanism is that the sensor can be attracted by the induced magnetic force created by the solenoid along one radial direction only, and responds to an axial force on the magnetic rod attached to the round plate, creating an axial attraction on the FBG. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

The effect of ball milling before and after calcination on the magnetic properties of HTR processed strontium hexaferrite powder

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2004
S. A. Seyyed Ebrahimi
Abstract HTR process (Hydrogen Treatment and Recalcination) is a very new method in which strontium hexaferrite powder, as produced conventionally from strontium carbonate and iron oxide, has been heated in a hydrogen static atmosphere and then recalcined in air. During the hydrogenation stage, the hard magnetic powder is changed to a soft magnetic material with a low intrinsic coercivity and high saturation magnetisation. However, after recalcination, the saturation magnetisation returns to its initial value, but intrinsic coercivity increases to a value much greater than its amount before hydrogenation. The intrinsic coercivity which has been reported in this regard is about 391 kA/m. In this work this HTR processed powder has been milled in a ball mill and effect of milling before and after calcination on microstructure and particularly magnetic properties has been investigated. The results show a good enhancement in the intrinsic coercivity of material. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Influence of nanocrystalization on magnetoelastic Villari effect in Fe73.5Nb3Cu1Si13.5B9 alloy

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 3-5 2003
R. Szewczyk
Abstract The results of an investigation of the influence of thermal annealing on the magnetoelastic properties of Fe73.5Nb3Cu1Si13.5B9 soft magnetic alloy in both amorphous and nanocrystalline state are presented. A new method developed was used to apply uniform compressive stresses to the investigated ring core made of the alloy. The compressive stresses produced by external mechanical forces were applied perpendicularly to the direction of the magnetizing field. Due to the uniform distribution of stresses in the core brittle nanocrystalline alloys may be tested for stresses up to 10 MPa. The results revealed, that process of nanocrystallisation causes significant increase in the stress sensitivity of the Fe73.5Nb3Cu1Si13.5B9 alloy. Moreover the influence of stresses caused by external forces is more significant at relatively low values of the magnetizing field suggesting that these nanocrystalline soft magnetic materials are stress sensitive in the range of technical operation of inductive components based on such materials. [source]

Humidity-Sensitive Magnet Composed of a Cyano-Bridged CoII,NbIV Dimetallic Assembly

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 26 2010
Kenta Imoto
Abstract Nanoporous magnetic materials composed of metal-assembled complexes are expected to exhibit chemical sensitivity. In this work, we observed a humidity-induced reversible change between ferromagnetism and antiferromagnetism in a new type of a cobalt octacyanoniobate based magnet in the high-humidity region. This humidity response is caused by the adsorption and desorption of non-coordinated water (so-called zeolitic water) molecules in the interstitial site. Such a phenomenon is achieved by the structural flexibility of an octacyanometalate-based magnet. [source]

Soft magnetic materials for electrical engineering: state of the art and recent advances

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 6 2005
F. Alves
Abstract This article gives a brief description of the essential characteristics and principal applications of amorphous, crystalline and nanostructured soft magnetic materials in electrical engineering. Copyright © 2005 John Wiley & Sons, Ltd. [source]

From Ag Nanoprisms to Triangular AuAg Nanoboxes

ADVANCED FUNCTIONAL MATERIALS, Issue 8 2010
Damian Aherne
Abstract In recent years, galvanic replacement reactions have been successfully employed to produce hollow bimetallic nanostructures of a range of shapes, yet to date there has been no example of the formation of hollow triangular AuAg nanostructures from a Ag nanoprism template. In this manuscript the first example of the synthesis of enclosed triangular AuAg nanostructures (triangular nanoboxes) via galvanic replacement reactions from Ag nanoprisms is reported. These triangular nanoboxes are studied by TEM and HAADF-STEM imaging to elucidate their structure. These studies show that the nanostructures are hollow and do not consist of a Ag core surrounded by a Au shell. Discrete dipole approximation calculations for the extinction spectra are carried out and provide additional evidence that the nanostructures are hollow. These new triangular nanoboxes are very attractive candidates for encapsulation and transport of materials of interest such as drugs, radioisotopes, or magnetic materials. [source]

The reduced scalar potential in regions with permeable materials: Reasons for loss of accuracy and cancellation

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 4 2007
S. Balac
Abstract Practical three-dimensional magnetic field problems usually involve regions containing current sources as well as regions with magnetic materials. For computational purposes, the use of the reduced scalar potential (RSP) as unknown has the advantage to transform a problem for a vector field throughout the space into a problem for a scalar function, thus reducing the number of degrees of freedom in the discretization. However, in regions with high magnetic permeability the use of the RSP alone usually results in severe loss in accuracy and it is recommended to use both the RSP and the total scalar potential. Using an asymptotic expansion, we investigate theoretically the underlying reasons for this lack of accuracy in permeable regions when using the RSP as a unique potential. Moreover, this investigation leads to an efficient numerical method to compute the magnetic field in regions with high magnetic permeability. Copyright © 2007 John Wiley & Sons, Ltd. [source]

A single-crystal time-of-flight neutron diffractometer at a spallation neutron source

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2007
Miwako Takahashi
A single-crystal diffractometer using the time-of-flight (TOF) Laue technique had been operated for studies of structural and magnetic disorder and phase transitions in alloys and magnetic materials at the pulsed spallation neutron source facility of the KEK Neutron Science Laboratory (KENS). In various sample environments, the diffractometer has demonstrated its usefulness in measurements of diffuse scattering for studying local structures, and in surveys of reciprocal space for studying phase transitions and incommensurate structures under the conditions of varying temperature and magnetic field. Particular emphasis is placed on the fact that though the instrument did not receive high-flux neutrons for long wavelengths suitable for the studies of magnetic scattering, it gave good results on the observations of magnetic diffuse scattering and superlattice reflections. Remarks and future tasks of the TOF Laue technique are discussed in relation to the asymmetric pulse shape, separation of the inelastic scattering, and dependence of data correction on the sample quality. [source]

X-ray birefringence and dichroism obtained from magnetic materials

JOURNAL OF SYNCHROTRON RADIATION, Issue 4 2001
S. W. Lovesey
In the past decade, synchrotron radiation has triggered a surge in studies of the polarization dependence of X-ray beams passing through non-isotropic materials. A vast range of experimental results concerning polarization-dependent absorption (dichroism) and dispersion (birefringence, for example) are available from materials which are either magnetic or exhibit preferred directions due to the local atomic environment. This article aims to bring together the diversity of modern experiments in this field with established methods of optical calculus, in a way that highlights the simplicity of the underlying physics. A useful framework is formed when observable quantities, in the X-ray case, are related to atomic variables of the sample material. Atomic descriptions of absorption spectra with various levels of complexity are considered, and some well documented sum-rules are encountered. The framework is the most general allowed within the electric dipole approximation. By way of illustration, dichroic X-ray absorption by two materials with highly anisotropic properties and magnetic ions with different valence shells are considered; namely, a 3d -transition ion in ferrous niobate, and a lanthanide ion in dysprosium borocarbide. Both materials display interesting magnetic properties that are challenging to interpret at an atomic level of detail, and it is shown how absorption experiments can contribute to resolving some issues. [source]

Femtosecond electron diffraction: Direct probe of ultrafast structural dynamics in metal films

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2009
Shouhua Nie
Abstract Femtosecond electron diffraction is a rapidly advancing technique that holds a great promise for studying ultrafast structural dynamics in phase transitions, chemical reactions, and function of biological molecules at the atomic time and length scales. In this paper, we summarize our development of a tabletop femtosecond electron diffractometer. Using a delicate instrument design and careful experimental configurations, we demonstrate the unprecedented capability of detecting submilli-ångström lattice spacing change on a subpicosecond timescale with this new technique. We have conducted an in-depth investigation of ultrafast coherent phonon dynamics induced by an impulsive optical excitation in thin-film metals. By probing both coherent acoustic and random thermal lattice motions simultaneously in real time, we have provided the first and unambiguous experimental evidence that the pressure of hot electrons contributes significantly to the generation of coherent acoustic phonons under nonequilibrium conditions when electrons and phonons are not thermalized. Based on these observations, we also propose an innovative approach to measure the electronic Grüneisen parameter in magnetic materials at and above room temperature, which provides a way to gain new insights into electronic thermal expansion in ferromagnetic transition metals. Microsc. Res. Tech. 2009. © 2009 Wiley-Liss, Inc. [source]

Erratum: On the advantages of magnetic materials in microstrip antenna miniaturization

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2010
Pekka Ikonen
Originally published in Microwave Opt Technol Lett 50: 3131,3134, 2008 . © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 247, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24890 [source]

Dual Chromophore-Nitroxides: Novel Molecular Probes, Photochemical and Photophysical Models and Magnetic Materials

Oxidation-induced high-Curie-temperature ferromagnetism in CoAl(100)

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2007
V. Rose
Abstract In conventional magnetic materials, oxidation is a disagreeable effect that often lowers or destroys the magnetic capabilities of those materials. By contrast, we report on the decisive paramagnetic-ferromagnetic phase transition in CoAl(100) at room temperature, utilizing oxidation of stoichiometric CoAl. We also discuss the control and drastic increase of the coercive field by subsequent annealing of the oxidized sample. The alumina film grown by selective oxidation protects the alloy from oxidation of Co, despite the accumulation of Al vacancies and the resulting enrichment in Co of the metallic phase underneath the oxide film. As a result, a ferromagnetic thin Co-rich phase is formed at the interface between the insulating aluminum oxide and the paramagnetic Co50Al50 bulk. The creation via simple oxidation of a ferromagnetic thin film underneath a surface insulator demonstrates a novel path to building the majority of a magnetic tunnel junction. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Proceedings of the Second Seeheim Conference on Magnetism (SCM2004)

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2004
Mohammad Ghafari
The Second Seeheim Conference on Magnetism took place in Seeheim, Germany, 27 June,1 July 2004. SCM2004 focused on latest developments in the field of magnetism of nano-structured materials, surfaces, interfaces and nanoparticles. These novel materials are connected with many aspects of magnetism such as hard and soft magnetic materials, magnetic interactions, magnetization processes, spin dependent transport properties, and applications. [source]

Preface: phys. stat. sol. (c) 1/12

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2004
Chair person Mohammad Ghafari
The Second Seeheim Conference on Magnetism (SCM2004) was the second conference in the tri-annual series of this conference series on magnetism, organized under the auspices of Darmstadt University of Technology, Forschungszentrum Karlsruhe and Ulm University. SCM2004 was held from 27 June to 1 July 2004. The location was the Lufthansa Training Center in Seeheim located conveniently in central Germany and easily accessible by air, train and car. The purpose of the meeting was to provide an opportunity to present and discuss recent developments in the field of magnetic nanomaterials. SCM2004 was focused on the latest developments in specific areas of magnetism (nanostructured materials, surfaces, interfaces and nanoparticles) and covered fundamental aspects of magnetism as well as applications. The most recent results were presented in the form of invited and contributed talks as well as posters. The topical areas were: ,,hard and soft magnetic materials ,,magnetic interactions ,,magnetization processes ,,spin dependent transport properties ,,nanostructured materials ,,applications. The first conference of this series was held in Seeheim in 2001. The papers from the 2001 conference were published in a regular issue of physica status solidi (a) 189, Nos. 2, 3 (2002), and since their publication they have been downloaded from the Web more than 14,000 times. This cleary demonstrates both the interest in and the need for this conference series. Our second meeting was attended by participants from 36 countries. A total number of 271 papers correlating nanostructure and magnetic properties were selected for presentation. Throughout the meeting a total of 51 talks was given; the remaining 220 papers were selected for poster presentation. The conference proceeded in an informal and very friendly atmosphere among the researchers from various parts of the world. We are grateful to the Deutsche Forschungsgemeinschaft, Forschungszentrum Karlsruhe and Darmstadt University of Technology for their kind financial support. We are looking forward to welcoming again participants of SCM2004 at the Third Seeheim Conference on Magnetism, planned for 2007 in Seeheim. [source]

Novel highly elastic magnetic materials for dampers and seals: Part I. Preparation and characterization of the elastic materials

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 11 2007
S. Abramchuk
Abstract The new generation of magnetic elastomers represents a new type of composites, consisting of small (mainly nano and micron-sized) magnetic particles dispersed in a highly elastic polymeric matrix. The combination of polymers with magnetic materials displays novel and often enhanced properties. Highly elastic magnetic composites are quite new and understanding of the behavior of these materials depending on the composition, external conditions, and the synthesis processes is still missing. Thus, the aim of this work is the study of fundamental principles governing the preparation of these materials as well as their structure and elastic properties. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Novel highly elastic magnetic materials for dampers and seals: part II.

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 7 2007
Material behavior in a magnetic field
Abstract The combination of polymers with magnetic particles displays novel and often enhanced properties compared to the traditional materials. They can open up possibilities for new technological applications. The magnetic field sensitive elastomers represent a new type of composites consisting of small particles, usually from nanometer range to micron range, dispersed in a highly elastic polymeric matrix. In this paper, we show that in the presence of built-in magnetic particles it is possible to tune the elastic modulus by an external magnetic field. We propose a phenomenological equation to describe the effect of the external magnetic field on the elastic modulus. We demonstrate the engineering potential of new materials on the examples of two devices. The first one is a new type of seals fundamentally different from those used before. In the simplest case, the sealing assembly includes a magnetoelastic strip and a permanent magnet. They attract due to the magnetic forces. This ensures that due to high elasticity of the proposed composites and good adhesion properties, the strip of magnetoelastic will adopt the shape of the surface to be sealed, this fact leading to an excellent sealing. Another straightforward application of the magnetic composites is based on their magnetic field dependent elastic modulus. Namely, we demonstrate in this paper the possible application of these materials as adjustable vibration dampers. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Electron-density studies of molecular magnetic materials

ACTA CRYSTALLOGRAPHICA SECTION A, Issue 5 2004
Sébastien Pillet
For more than forty years, the experimental determination and analysis of electron densities have played a fundamental role in advances in the chemical bond concept. The present paper illustrates the application of this approach to the field of molecular magnetism with examples that recently appeared in the literature. Particular attention is attached to several classes of materials, purely organic free radicals, coordination compounds and organometallic complexes, which exhibit specific magnetic behaviors. It is shown to what extent the electron-density analysis can shed light on bonding aspects that are closely related to magnetic couplings. Relations between spin delocalization, spin polarization, superexchange and the characteristics of the electron density are described. The use of the topological theory of `atoms in molecules' allows the possible magnetic interaction pathways to be located and defined, especially through weak intermolecular contacts. The complementarity with polarized neutron diffraction and spin-density modeling techniques is particularly evident from the chosen examples. [source]

Self-regulating hyperthermia induced using thermosensitive ferromagnetic material with a low Curie temperature

CANCER SCIENCE, Issue 4 2008
Hajime Saito
Hyperthermia has been used for many years to treat a variety of malignant tumors. The Curie temperature (Tc) is a transition point at which magnetic materials lose their magnetic properties, causing a cessation of current and thus heat production. The Tc enables automatic temperature control throughout a tumor as a result of the self-regulating nature of the thermosensitive material. We have developed a method of magnetically-induced hyperthermia using thermosensitive ferromagnetic particles (FMPs) with low Tc (43°C), enough to mediate automatic temperature control. B16 melanoma cells were subcutaneously injected into the backs of C57BL/6 mice, after which tumors were allowed to grow to 5 mm in diameter. FMPs were then injected into the tumors, and the mice were divided into three groups: group I (no hyperthermia, control); group II (one hyperthermia treatment); and group III (hyperthermia twice a week for 4 weeks). When exposed to a magnetic field, the FMPs showed a sharp rise in heat production, reaching the Tc in tissue within 7 min, after which the tissue temperature stabilized at approximately the Tc. In groups I and II, all mice died within 30,45 days. In group III, however, 6 of 10 mice remained alive 120 days after beginning treatment. Our findings suggest that repeated treatment with magnetically-induced self-regulating hyperthermia, mediated by FMPs with a low Tc, is an effective means of suppressing melanoma growth. A key advantage of this hyperthermia system is that it is minimally invasive, requiring only a single injection for repeated treatments with automatic temperature control. (Cancer Sci 2008; 99: 805,809) [source]