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Phase Transformation (phase + transformation)
Kinds of Phase Transformation Selected AbstractsSyntheses, Crystal Structures, and the Phase Transformation of Octacyanometallate-Based LnIII,WV Bimetallic Assemblies with Two-Dimensional Corrugated LayersEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2010Ai-Hua Yuan Abstract The reactions between Ln(NO3)3·nH2O and (Bu3NH)3[W(CN)8]·H2O have led to two series of octacyanometallate-based complexes: Ln(H2O)5[W(CN)8] [Ln = La(1), Pr(2), Nd(3), Eu(4), Gd(5)] and Ln(H2O)4[W(CN)8] [Ln = Ho(6), Er(7), Tm(8), Lu(9)]. The crystal structures of 1,9 have two-dimensional corrugated layers in which the LnIII and WV centres are linked in an alternating fashion. Thermogravimetric (TG) and powder XRD results reveal the presence of a phase transformation in the LnIII,WV system with increasing atomic number of the LnIII atoms. [source] Magnetic Field-Induced Phase Transformation in NiMnCoIn Magnetic Shape-Memory Alloys,A New Actuation Mechanism with Large Work OutputADVANCED FUNCTIONAL MATERIALS, Issue 7 2009Haluk E. Karaca Abstract Magnetic shape memory alloys (MSMAs) have recently been developed into a new class of functional materials that are capable of magnetic-field-induced actuation, mechanical sensing, magnetic refrigeration, and energy harvesting. In the present work, the magnetic &!hyphen;field-induced martensitic phase transformation (FIPT) in Ni45Mn36.5Co5In13.5 MSMA single crystals is characterized as a new actuation mechanism with potential to result in ultra-high actuation work outputs. The effects of the applied magnetic field on the transformation temperatures, magnetization, and superelastic response are investigated. The magnetic work output of NiMnCoIn alloys is determined to be more than 1,MJ m,3 per Tesla, which is one order of magnitude higher than that of the most well-known MSMAs, i.e., NiMnGa alloys. In addition, the work output of NiMnCoIn alloys is orientation independent, potentially surpassing the need for single crystals, and not limited by a saturation magnetic field, as opposed to NiMnGa MSMAs. Experimental and theoretical transformation strains and magnetostress levels are determined as a function of crystal orientation. It is found that [111]-oriented crystals can demonstrate a magnetostress level of 140,MPa T,1 with 1.2% axial strain under compression. These field-induced stress and strain levels are significantly higher than those from existing piezoelectric and magnetostrictive actuators. A thermodynamical framework is introduced to comprehend the magnetic energy contributions during FIPT. The present work reveals that the magnetic FIPT mechanism is promising for magnetic actuation applications and provides new opportunities for applications requiring high actuation work-outputs with relatively large actuation frequencies. One potential issue is the requirement for relatively high critical magnetic fields and field intervals (1.5,3,T) for the onset of FIPT and for reversible FIPT, respectively. [source] Martensitic Phase Transformation of Isolated HfO2, ZrO2, and HfxZr1,,,xO2 (0,<,x,<,1) Nanocrystals,ADVANCED FUNCTIONAL MATERIALS, Issue 10 2005J. Tang Abstract We previously reported that, during the reactions to make nanocrystals of HfO2 and Hf-rich HfxZr1,,,xO2, a tetragonal-to-monoclinic phase transformation occurs that is accompanied by a shape change of the particles (faceted spherical to nanorods) when the temperature at which the reaction is conducted is changed from 340,to 400,°C. We now conclude that this concomitant phase and shape change is a result of the martensitic transformation of isolated nanocrystals in a hot liquid, where twinning plays a crucial role in accommodating the shape-change-induced strain. That such change was not observed during the reactions forming ZrO2 and Zr-rich HfxZr1,,,xO2 nanocrystals is attributed to the higher driving force needed in those instances compared to that needed for producing HfO2 and Hf-rich HfxZr1,,,xO2 nanocrystals. We also report here the post-synthesis, heat-induced phase transformation of HfxZr1,,,xO2 (0,<,x,<,1) nanocrystals. As temperature increases, all the tetragonal nanocrystals transform to the monoclinic phase accompanied by an increase in particle size (as evidenced by X-ray diffraction and transmission electron microscopy), which confirms that there is a critical size for the phase transformation to occur. When the monoclinic nanorods are heated above a certain temperature the grains grow considerably; under certain conditions a small amount of tetragonal phase appears. [source] Phase Transformation and Densification Behavior of Microwave-Sintered Si3N4,Y2O3,MgO,ZrO2 SystemINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 1 2009Sreekumar Chockalingam A 2.45 GHz microwave-sintered Si3N4,Y2O3,MgO system containing various amounts of ZrO2 secondary additives have been studied with respect to phase transformation and densification behavior. The temperature dependent dielectric properties were measured from 25°C to 1400°C using a conventional cavity perturbation technique. Phase transformation behavior was studied using X-ray diffractometry. Microwave sintered results were compared with those of conventional sintered results. It has been found that , to , phase transformation was completed at a lower temperature in microwave-sintered samples than those of the conventionally sintered samples. Density of the microwave-sintered samples increased up to 2.5 wt% of ZrO2 addition and thereafter it showed a tendency to decrease or remain constant. The decrease in density is attributed to the pore generation caused by decomposition due to the localized over heating. [source] Reversibility of the Perovskite-to-Fluorite Phase Transformation in Lead-Based Thin and Ultrathin Films,ADVANCED MATERIALS, Issue 8 2008Geoff L. Brennecka As film thicknesses decrease below 50 nm, control of cation stoichiometry in Pb-based dielectrics becomes increasingly difficult, a problem that is exacerbated by interaction with technologically important Pt bottom electrodes. Post-crystallization annealing in a Pb-rich atmosphere is shown to be a general technique to reversibly convert low-permittivity Pb-deficient fluorite into ferroelectric high-permittivity stoichiometric perovskite with outstanding dielectric properties (see figure). [source] Formation of Nb2O5 Nanotube Arrays Through Phase Transformation**,ADVANCED MATERIALS, Issue 5 2008C. Yan The successful synthesis of monoclinic Nb2O5nanotube arrays (see figure) from pseudo-hexagonal Nb2O5 nanorod arrays is reported; the synthesis is based on phase transformation accompanied by void formation, where voids can be intriguingly generated during phase transformation. A key parameter for achieving nanotube growth is the energy difference between the pseudo-hexagonal and monoclinic Nb2O5 nanostructures, which determines the phase transformation. [source] Thickness-Driven Orthorhombic to Triclinic Phase Transformation in Pentacene Thin Films,ADVANCED MATERIALS, Issue 7 2005F. Drummy Pentacene films are thermally evaporated onto amorphous carbon-coated mica substrates held at room temperature. The crystal structure and morphology of the films are analyzed using electron microscopy and diffraction, and a new orthorhombic structure is characterized for films below a critical thickness (see Figure). Evidence that the orthorhombic structure is thermodynamically stable at low film thickness due to its low (001) surface energy is obtained. [source] Phase Transformation and Tunable Piezoelectric Properties of Lead-Free (Na0.52K0.48,xLix)(Nb1,x,ySbyTax)O3 SystemJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2009Ruzhong Zuo Lead-free (Na0.52K0.48,x)(Nb1,x,ySby)O3 - xLiTaO3 (NKNS,LT) piezoelectric ceramics have been fabricated by ordinary sintering. A special attention was paid to the composition design through which the dielectric and piezoelectric properties of the (Li, Ta, Sb) modified NKN systems were significantly promoted. A property spectrum was generated with a particular discussion on the relationship between the Sb content, the LT content, the polymorphic phase transition, and the electrical properties and their temperature stability. Excellent and tunable electrical properties of d33=242,400 pC/N, kp=36%,54%, , and Tc=230°,430°C demonstrate a tremendous potential of the compositions studied for device applications. [source] Growth and Phase Transformation of Nanometer-Sized Titanium Oxide Powders Produced by the Precipitation MethodJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2004Gwan Hyoung Lee We report an in situ TEM investigation of the growth and transformation in nanometer-sized titania powders. The powders were produced through precipitation of titanium tetrachloride under different pH conditions. The initial phase of the produced powders was amorphous or was a mixture of anatase and brookite according to the pH conditions. During calcination, the anatase particles grew and transformed into rutile. The transformation temperature increased with increasing pH value. In situ TEM observations showed that the anatase particles were absorbed into rutile, and then rutile particles grew by coalescence. Furthermore, small pores were observed to form in samples prepared with high pH from the effects of hydroxyl ions and zeta potential. Pore formation increased the surface area, which delayed the transformation and nucleation of rutile. This explains the difference of growth and transformation of titania powders produced under different pH conditions during calcination. [source] Laminar Ceramics Utilizing the Zirconia Tetragonal-to-Monoclinic Phase Transformation to Obtain a Threshold StrengthJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2002Michael G. Pontin Ceramic laminates have been fabricated with thin layers, containing a mixture of unstabilized zirconia (MZ-ZrO2) and alumina (Al2O3), sandwiched between thicker layers of alumina that contain a small fraction of Y2O3 -stabilized tetragonal ZrO2 to inhibit grain growth. The MZ-ZrO2 undergoes a tetragonal-to-monoclinic phase transformation during cooling to produce biaxial compressive stresses in the thin layers. Cracks that extend within the thicker alumina layers can be arrested by the compressive layers to produce a threshold strength, i.e., a strength below which the probability of failure is zero. Laminates composed of Al2O3 layers 315 ± 15 ,m thick and Al2O3/MZ-ZrO2 layers 29 ± 3 ,m thick exhibit a threshold strength of 507 ± 36 MPa, regardless of the MZ-ZrO2 content, for volume fractions ,0.35. These results, piezospectroscopic stress measurements, and microstructural observations suggest that microcracking produced during the transformation reduces the magnitude of the compressive stresses achieved, which in turn limits the magnitude of the threshold strength. [source] Electrical Resistivity and Phase Transformation in SteelsMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 1 2003O. N. Mohanty Elektrischer Widerstand; Phasenumwandlung; Magnetische Eigenschaften Abstract Changes in electrical resistance accompanying transformations in steels with magnetic change (e.g. , , martensite/bainite) and without magnetic change (e.g. , , ,, above Curie temperature) have been examined; the former class affects the resistivity the latter does not. Next, while the efficacy of electrical resistivity measurement in capturing the well-known features of austenite stabilization (e.g. over , ageing, reversibility, and influence of prior martensite amount and so on) in high carbon steels has been reported in an earlier publication, new features (e.g. increase in resistance -increase at very low temperatures, change in temperature co-efficient of resistivity in the stabilized material etc.) are highlighted here. Finally, the work shows that a quantitative estimate of precipitation in the copper bearing, age-hardenable HSLA-100 steel during tempering can be done by continuous electrical resistivity measurement. These data also allow an in-depth kinetic analysis using the Johnson-Mehl-Avrami equation. Zusammenhang zwischen elektrischem Widerstand und Phasenumwandlungen in Stählen Änderungen des elektrischen Widerstands wurden im Zusammenhang mit Phasenumwandlungen, die zu Änderungen der magnetischen Eigenschaften führen (z.B. , , Martensit/Bainit), und solchen, die keine Änderungen der magnetischen Eigenschaften bewirken (z.B. , , , oberhalb der Curie-Temperatur), untersucht. Während sich die erste Umwandlungsart auswirkt, gilt dies für die andere nicht. Während über die Empfindlichkeit von Widerstandsmessungen zur Erfassung der Austenitstabilisierung (z.B. Überalterung, Umkehrbarkeit, Einfluß des vorher vorhandenen Martensitanteils, usw.) in übereutektoiden Stählen in einer früheren Veröffentlichung berichtet wurde, wird im zweiten Teil der hier vorgelegten Veröffentlichung auf neuerdings erfassbare Merkmale (z.B. der Anstieg des Widerstands bei sehr niedrigen Temperaturen, die Änderung der Temperaturabhängigkeit des Widerstands im stabilisierten Material, usw.) eingegangen. Schließlich zeigt die Arbeit, daß durch kontinuierliche Widerstandsmessungen während des Anlassens eine quantitative Abschätzung der Ausscheidungsgehalte im kupferhaltigen, ausscheidungsverfestigenden HSLA-100-Stahl erfolgen kann. Die Daten hierzu erlauben zudem eine vertiefte kinetische Analyse auf Basis der Johnson-Mehl-Avrami-Gleichung. [source] Reversible and Efficient Materials-based Actuation by Electrolytic Phase TransformationCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 9 2003C.G. Cameron Abstract Electrolytic phase transformation is presented as a means of inducing reversible actuation in devices operating in a wide range of applications and scales. The device exploits the enormous pressure and volume changes that accompany the electrochemical interconversion between liquid and gas phases. With this method, strains beyond 136,000 % and stresses surpassing 200 MPa can be achieved, offering a level of performance many orders of magnitude beyond that of other materials-based strategies. [source] Crystal Structures and Phase Transformation of Deuterated Lithium Imide, Li2ND.CHEMINFORM, Issue 43 2006Michael P. Balogh Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Evidence for the Existence of ,-Na3AlH6: Monitoring the Phase Transformation from ,-Na3AlH6 by in situ Methods.CHEMINFORM, Issue 40 2005C. Weidenthaler Abstract For Abstract see ChemInform Abstract in Full Text. [source] Wet-Chemical Synthesis and Martensitic Phase Transformation of Au,Cd Nanoparticles with Near-Equiatomic Composition.CHEMINFORM, Issue 46 2004Christoph Frommen Abstract For Abstract see ChemInform Abstract in Full Text. [source] Phase Transformation and the Type of Lattice Distortion of Some Platinum-Rich Phases Belonging to the Cu Family.CHEMINFORM, Issue 25 2003H. Meininger Abstract For Abstract see ChemInform Abstract in Full Text. [source] Phase Transformations During High-Pressure Torsion of Pure Zr and of a Zr-2.5%Nb Alloy,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Alexander P. Zhilyaev Zirconium at normal conditions (room temperature and atmospheric pressure) has an HCP structure with lattice parameters a,=,3.2313,Å and c,=,5.1477,Å (,-phase). During loading under hydrostatic conditions in diamond anvil cells, a transition from the , -phase to an , -phase occurs at a pressure between 2 and 6 GPa and from , to , (bcc) at 30 GPa. It has been recently reported that the , to ,,+,, transformation might be induced by HPT processing. The resulting microstructures are stable at room temperature and atmospheric pressure. This paper explores the influence of previous processing steps and of composition in the feasibility of the HPT induced , to ,,+,, transformation. It will be shown that neither previous quenching nor high temperature HPT processing prevents the transformation from occurring during subsequent room temperature HPT. The addition of elements such as Nb also seems to favor the transformation. Understanding well the potential of HPT to stabilize high-pressure phases at normal conditions might be critical, as it will open a whole new range of applications for already existing materials. [source] Global Techniques for Characterizing Phase Transformations , A Tutorial ReviewADVANCED ENGINEERING MATERIALS, Issue 6 2010Michel Perez To characterize phase transformations, it is necessary to get both local and global information. No experimental technique alone is capable of providing these two types of information. Local techniques are very useful to get information on morphology and chemistry but fail to deal with global information like phase fraction and size distribution since the analyzed volume is very limited. This is why, it is important to use, in parallel, global experimental techniques, that investigate the response of the whole sample to a stimulus (electrical, thermal, mechanical,). The aim of this paper is not to give an exhaustive list of all global experimental techniques, but to focus on a few examples of recent studies dealing with the characterization of phase transformations, namely (i) the measurement of the solubility limit of copper in iron, (ii) the tempering of martensite, (iii) the control of the crystallinity degree of a ultra high molecular weight polyethylene and (iii) a precipitation sequence in aluminum alloys. Along these examples, it will be emphasized that any global technique requires a calibration stage and some modeling to connect the measured signal with the investigated information. [source] Thermally Induced Reversible Phase Transformations Accompanied by Emission Switching Between Different Colors of Two Aromatic-Amine CompoundsADVANCED MATERIALS, Issue 31 2009Yunfeng Zhao Thermally driven reversible emission switching between different colors and solid-phase transformation are investigated for two aromatic-amine compounds bearing trifluoromethyl (CF3) groups. The phase-dependent emission properties are attributed to the different molecular packing properties and changeable molecular geometry for different solid phases (see figure). [source] Phase Transformations in the High-Temperature Form of Pure and TiO2 -Stabilized Ta2O5JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2007Geoff L. Brennecka The high-temperature forms of undoped tantalum pentoxide (H-100Ta2O5) and TiO2,modified Ta2O5 (H-92Ta2O5,8TiO2) were investigated by in situ synchrotron X-ray diffraction and Raman scattering measurements. Two unquenchable and reversible phase transformations were observed in pure H-Ta2O5, while only one was detected for TiO2 -stabilized H-Ta2O5. Diffraction studies were consistent with displasive transformations, but hot-stage Raman spectroscopy indicated the existence of transient intermediate forms during the transformations. Use of complementary techniques enabled the reinterpretation of phase transformations in light of a newly proposed crystal structure model for H-Ta2O5,1 and emphasized the structural contributions of the oxygen sublattice. [source] Effect of Yttrium and Erbium Ions on Epitaxial Phase Transformations in AluminaJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2003Deirdre D. Ragan The effect of low concentrations of Y, Er, and Cr solutes on the amorphous-to-, transformation and on the ,-to-, transformation in aluminum oxide has been studied in situ by time-resolved reflectivity. The activation energies of the two transformations with these dopants are the same as in undoped alumina, being 4.1 ± 0.1 and 5.2 ± eV, respectively. Although not affecting the activation energies, Y, Er, and Cr do affect the transformation kinetics. Y and Cr ions decrease the ,-to-, transformation velocity and, over the limited range studied, do so in proportion to their concentration. Concentrations of Er as low as ,6 ppm retard the ,-to-, transformation and concentrations of 32 ppm essentially stop the transformation occurring within the times and temperatures accessible within the present experiment, thereby preventing quantification of the effect of Er on the ,-phase transformation. Erbium also retards the amorphous-to-, transformation relative to undoped alumina whereas yttrium and chromium accelerate it. [source] Crystallite and Grain-Size-Dependent Phase Transformations in Yttria-Doped ZirconiaJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2003Arun Suresh In pure zirconia, ultrafine powders are often observed to take on the high-temperature tetragonal phase instead of the "equilibrium" monoclinic phase. The present experiments and analysis show that this observation is one manifestation of a much more general phenomenon in which phase transformation temperatures shift with crystallite/grain size. In the present study, the effect of crystallite (for powders) and grain (for solids) size on the tetragonal , monoclinic phase transformation is examined more broadly across the yttria,zirconia system. Using dilatometry and high-temperature differential scanning calorimetry on zirconia samples with varying crystallite/grain sizes and yttria content, we are able to show that the tetragonal , monoclinic phase transformation temperature varies linearly with inverse crystallite/grain size. This experimental behavior is consistent with thermodynamic predictions that incorporate a surface energy difference term in the calculation of free-energy equilibrium between two phases. [source] Effect of MgO Doping on the Phase Transformations of BaTiO3JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2000Toru Nagai The successive phase transformations in MgO-doped BaTiO3 were studied. Upon MgO doping, dielectric anomalies corresponding to lower phase transformations were broadened and depressed, while an anomaly for a cubic,tetragonal transformation remained and shifted to a lower temperature. XRD peak splitting upon tetragonality of BaTiO3 was decreased, and the peaks exhibited abnormally broadened profiles which are different from the one for cubic BaTiO3 above Tc. Raman spectroscopy revealed the existence of orthorhombic phase at room temperature for the solid solution with 0.5 mol% or more MgO. The temperature dependence of the Raman spectrum showed that orthorhombic and rhombohedral phases in MgO-doped BaTiO3 were stabilized at higher temperatures than pure BaTiO3. [source] Pressure-Induced Amorphization and Phase Transformations in ,-LiAlSiO4.CHEMINFORM, Issue 35 2005Jianzhong Zhang Abstract For Abstract see ChemInform Abstract in Full Text. [source] X-Ray Diffraction Studies and Phase Transformations of CeNbO4+, Using in situ Techniques.CHEMINFORM, Issue 7 2004S. J. Skinner Abstract For Abstract see ChemInform Abstract in Full Text. [source] Phase transformation of erythromycin A dihydrate during fluid bed dryingJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2008Meike Römer Abstract An in-line near infrared (NIR) spectrometer was employed to monitor phase transformations of erythromycin dihydrate during a miniaturized fluid bed drying process. The pellets, containing 50% (w/w) erythromycin dihydrate and 50% (w/w) microcrystalline cellulose, were dried at 30, 45, and 60°C. Principal component analysis was used to determine solid-state changes. For this purpose the wavelength range of 1360,2000 nm was selected and preprocessed to remove multiplicative effects. Transformation to erythromycin dehydrate was observed for the pellets dried at 45 and 60°C by NIR spectrometry and X-ray powder diffractometry (XRPD). The formation of erythromycin dehydrate was observed at a moisture content 1.4% (w/w) (mass of water per dry mass of sample) while at 1.8% (w/w) neither XRPD nor NIR were able to detect dehydration. Transformation to erythromycin dehydrate therefore depends strongly on the moisture content of the pellets. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:4020,4029, 2008 [source] Formation and ageing of L-glutamic acid spherulitesCRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2010R. Beck Abstract Polycrystalline spherulites of L-glutamic acid have been crystallized by pH-shift precipitation from stirred aqueous solutions. The time dependent behaviour of the spherulites has been studied during the crystallization process and batch filtration tests have been performed. It has been shown that the FBRM mean chord length of the investigated spherulites decreases in the course of time. The fact that the size reduction progresses faster at higher temperature and the solubility of resuspended polycrystalline particles decreasing with time, implies an ageing mechanism to be responsible for the observed changes in the particle size. It has been shown that the surface area decreases with time, ruling out particle breakage as a possible explanation for the decrease in particle size. XRD and Raman studies of L-glutamic acid, however, show only marginal differences in the crystalline structure of particles obtained from different time stages. The ageing may occur due to several different mechanisms like phase transformation and Ostwald ripening. L-glutamic acid spherulites after 3 h exhibit a 3-fold higher value for the cake resistance as compared to particles after 0.5 h. However, particles obtained after 22 h exhibit an 8-fold lower cake resistance as compared to the initially obtained spherulites, The increase in the cake resistance is attributed to the appearance of small plate-like crystals and a change in the interaction between the crystal surface and the solution. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Flux growth of La-doped lead zirconate stannate titanate antiferroelectric crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 10 2008Lin Wang Abstract Relaxor antiferroelectric single crystals lead lanthanum zirconate stannate titanate (PLZST) with the composition around the morphotropic phase boundary (MPB) have been grown by flux method using 50 wt% PbO-PbF2 -B2O3 as a flux. The obtained crystals are light yellow in color. The XRD patterns revealed that the habitual faces of the obtained crystal are (001). The crystal morphology was studied and related to a layer growth mechanism controlled by two-dimensional growth. The chemical composition of as-grown crystal was analyzed by inductively coupled plasma atomic emission spectrometry (ICP), indicating a slight decrease of the amount of Ti compared to the starting materials. The result was verified by the XRD patterns with the phase transformation from the co-existence of tetragonal and rhombohedra phases to the single tetragonal phase. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Syntheses, Crystal Structures, and the Phase Transformation of Octacyanometallate-Based LnIII,WV Bimetallic Assemblies with Two-Dimensional Corrugated LayersEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2010Ai-Hua Yuan Abstract The reactions between Ln(NO3)3·nH2O and (Bu3NH)3[W(CN)8]·H2O have led to two series of octacyanometallate-based complexes: Ln(H2O)5[W(CN)8] [Ln = La(1), Pr(2), Nd(3), Eu(4), Gd(5)] and Ln(H2O)4[W(CN)8] [Ln = Ho(6), Er(7), Tm(8), Lu(9)]. The crystal structures of 1,9 have two-dimensional corrugated layers in which the LnIII and WV centres are linked in an alternating fashion. Thermogravimetric (TG) and powder XRD results reveal the presence of a phase transformation in the LnIII,WV system with increasing atomic number of the LnIII atoms. [source] New Routes for Fabricating Ultrafine-Grained Microstructures in Bulky Steels without Very-High Strains,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Nobuhiro Tsuji Abstract Several routes to produce ultrafine-grained structures in steels without severe plastic deformation are introduced. The key point of the ideas is to combine plastic deformation with the phase transformation of matrix phases. When as-quenched martensite in steels is used as a starting microstructure, sub-micrometer grain-sized structures can be obtained easily. Another example using a dual-phase steel composed of soft and hard phases is also discussed. Repeating plastic deformation and phase transformation is also effective in obtaining nanostructures in an austenitic stainless steel. Examples of strips of UFG stainless steels in industry and their applications are presented. [source] | |||||||||||||||||||||||||||||||||||||||||||