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K.h.j. Buschow - One of the best experts on this subject based on the ideXlab platform.
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Magnetic properties of Rare Earth Compounds of the type GdCo5−xBx
Journal of Alloys and Compounds, 1998Co-Authors: Z.g. Zhao, F.r. De Boer, K.h.j. BuschowAbstract:The magnetic properties of several Rare-Earth Compounds of the type RCo5−xBx were investigated by means of X-ray diffraction and measurements of the magnetisation in high magnetic fields. From the magnetic isotherms obtained on free powder particles at 4.2 K, we determined values of the spontaneous magnetisation and the Gd–Co intersublattice-coupling constant. It is shown that there is a very strong decrease of the Co moment with B concentration while the intersublattice-coupling constant remains virtually unaffected.
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Magnetic properties of Rare-Earth Compounds of the type R(Fe, Ni)10Si2
Physica B: Condensed Matter, 1997Co-Authors: H. Tang, F.r. De Boer, D. Zhang, E.h. Brück, K.h.j. BuschowAbstract:The magnetic properties of Rare-Earth Compounds of the type HoFe10-xNixSi2 were investigated by means of X-ray diffraction and measurements of the magnetisation and the AC-susceptibility. It is shown that these Compounds form a complete series of solid solution in which the tetragonal ThMn12-type of structure is retained for all concentrations. From magnetic measurements made on HoNi10Si2 and GdNi10Si2, it is shown that the presence of Fe moments is essential for the occurrence of magnetic ordering above 4.2 K. For sufficiently high Fe concentration a magnetic moment is induced on the Ni atoms.
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Magnetic properties of ternary Rare Earth Compounds of the type Y(Co,Ni)10Si2
Journal of Alloys and Compounds, 1996Co-Authors: H. Tang, F.r. De Boer, E.h. Brück, K.h.j. BuschowAbstract:Abstract The magnetic properties of Rare Earth Compounds of the type YCo10−xNixSi2 were investigated by means of X-ray diffraction on magnetically aligned powders and by measurements of the temperature dependence of the magnetisation and the a.c. susceptibility. From the experimental values of the saturation magnetisation at 4.2 k, we have determined that the magnitude of the Co moments in these Compounds decreases strongly with increasing Ni content. A similar strong decrease is displayed by the corresponding Curie temperatures. We have determined the easy magnetisation direction in the various YCo10−xNixSi2 Compounds and found that the Co sublattice anisotropy favours an easy moment direction perpendicular to the c-axis and decreases with increasing Ni concentration. The results obtained have been used to explain the concentration dependence of the spin-reorientation temperature in DyCo10−xNixSi2 Compounds.
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Diffusion of nitrogen in R2Fe17 (R = Rare Earth) Compounds determined by the Kissinger method
Journal of Alloys and Compounds, 1995Co-Authors: J. P. Liu, A.j.m. Winkelman, A.a. Menovsky, Hans Bakker, F.r. De Boer, K.h.j. BuschowAbstract:Abstract The activation energy of nitrogen diffusion in R 2 Fe 17 (R = Rare Earth) Compounds has been determined by applying the Kissinger method to analyse the differential scanning calorimetry (DSC) traces of nitrogenated R 2 Fe 17 Compounds. The nitrogen outgas that starts when the nitrides are heated above about 300 °C is a typical decomposition reaction of the type solid → solid + gas to which the Kissinger method can be applied. From the heating-rate dependence of the endothermic peaks in the DSC curves, values for the activation energy of nitrogen diffusion are derived. There is good agreement between the results for Sm 2 Fe 17 and Nd 2 Fe 17 obtained in the present investigation and the results reported in the literature which were obtained by means of other methods.
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permanent magnet materials based on tetragonal Rare Earth Compounds of the type rfe12 xmx
Journal of Magnetism and Magnetic Materials, 1991Co-Authors: K.h.j. BuschowAbstract:Abstract A review is given of the occurrence and composition of ternary Rare Earth Compounds RT12−xMx based on the tetragonal ThMn12 structure. Most of the Compounds form with T = Fe but there are also examples withT = Co, NiorMn. Particular attention is paid to the site preference of the nonmagnetic component M, (Al, Si, Ti, V, Cr, Mo, W, Re). A discussion is given of the magnetic properties of the RT12−xMx Compounds and the corresponding nitrides obtained after changing with nitrogen gas. The important role played by the intersublattice coupling on the magnetocrystalline anisotropy of these materials is stressed. Advantages and disadvantages of the RT12−xMx Compounds as permanent magnet materials are discussed.
F.r. De Boer - One of the best experts on this subject based on the ideXlab platform.
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Magnetic properties of Rare Earth Compounds of the type GdCo5−xBx
Journal of Alloys and Compounds, 1998Co-Authors: Z.g. Zhao, F.r. De Boer, K.h.j. BuschowAbstract:The magnetic properties of several Rare-Earth Compounds of the type RCo5−xBx were investigated by means of X-ray diffraction and measurements of the magnetisation in high magnetic fields. From the magnetic isotherms obtained on free powder particles at 4.2 K, we determined values of the spontaneous magnetisation and the Gd–Co intersublattice-coupling constant. It is shown that there is a very strong decrease of the Co moment with B concentration while the intersublattice-coupling constant remains virtually unaffected.
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Magnetic properties of Rare-Earth Compounds of the type R(Fe, Ni)10Si2
Physica B: Condensed Matter, 1997Co-Authors: H. Tang, F.r. De Boer, D. Zhang, E.h. Brück, K.h.j. BuschowAbstract:The magnetic properties of Rare-Earth Compounds of the type HoFe10-xNixSi2 were investigated by means of X-ray diffraction and measurements of the magnetisation and the AC-susceptibility. It is shown that these Compounds form a complete series of solid solution in which the tetragonal ThMn12-type of structure is retained for all concentrations. From magnetic measurements made on HoNi10Si2 and GdNi10Si2, it is shown that the presence of Fe moments is essential for the occurrence of magnetic ordering above 4.2 K. For sufficiently high Fe concentration a magnetic moment is induced on the Ni atoms.
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Magnetic properties of ternary Rare Earth Compounds of the type Y(Co,Ni)10Si2
Journal of Alloys and Compounds, 1996Co-Authors: H. Tang, F.r. De Boer, E.h. Brück, K.h.j. BuschowAbstract:Abstract The magnetic properties of Rare Earth Compounds of the type YCo10−xNixSi2 were investigated by means of X-ray diffraction on magnetically aligned powders and by measurements of the temperature dependence of the magnetisation and the a.c. susceptibility. From the experimental values of the saturation magnetisation at 4.2 k, we have determined that the magnitude of the Co moments in these Compounds decreases strongly with increasing Ni content. A similar strong decrease is displayed by the corresponding Curie temperatures. We have determined the easy magnetisation direction in the various YCo10−xNixSi2 Compounds and found that the Co sublattice anisotropy favours an easy moment direction perpendicular to the c-axis and decreases with increasing Ni concentration. The results obtained have been used to explain the concentration dependence of the spin-reorientation temperature in DyCo10−xNixSi2 Compounds.
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Diffusion of nitrogen in R2Fe17 (R = Rare Earth) Compounds determined by the Kissinger method
Journal of Alloys and Compounds, 1995Co-Authors: J. P. Liu, A.j.m. Winkelman, A.a. Menovsky, Hans Bakker, F.r. De Boer, K.h.j. BuschowAbstract:Abstract The activation energy of nitrogen diffusion in R 2 Fe 17 (R = Rare Earth) Compounds has been determined by applying the Kissinger method to analyse the differential scanning calorimetry (DSC) traces of nitrogenated R 2 Fe 17 Compounds. The nitrogen outgas that starts when the nitrides are heated above about 300 °C is a typical decomposition reaction of the type solid → solid + gas to which the Kissinger method can be applied. From the heating-rate dependence of the endothermic peaks in the DSC curves, values for the activation energy of nitrogen diffusion are derived. There is good agreement between the results for Sm 2 Fe 17 and Nd 2 Fe 17 obtained in the present investigation and the results reported in the literature which were obtained by means of other methods.
Harald Hillebrecht - One of the best experts on this subject based on the ideXlab platform.
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synthesis crystal structure and properties of mg3b36si9c and related Rare Earth Compounds re3 xb36si9c re y gd lu
Journal of Solid State Chemistry, 2013Co-Authors: Thilo Ludwig, Alexis Pediaditakis, Vanessa Sagawe, Harald HillebrechtAbstract:We report on the synthesis and characterisation of Mg{sub 3}B{sub 36}Si{sub 9}C. Black single crystals of hexagonal shape were yielded from the elements at 1600 °C in h-BN crucibles welded in Ta ampoules. The crystal structure (space group R3{sup ¯}m, a=10.0793(13) A, c=16.372(3) A, 660 refl., 51 param., R{sub 1}(F)=0.019; wR{sub 2}(F{sup 2})=0.051) is characterized by a Kagome-net of B{sub 12} icosahedra, ethane like Si{sub 8}-units and disordered SiC-dumbbells. Vibrational spectra show typical features of boron-rich borides and Zintl phases. Mg{sub 3}B{sub 36}Si{sub 9}C is stable against HF/HNO{sub 3} and conc. NaOH. The micro-hardness is 17.0 GPa (Vickers) and 14.5 GPa (Knoop), respectively. According to simple electron counting rules Mg{sub 3}B{sub 36}Si{sub 9}C is an electron precise compound. Band structure calculations reveal a band gap of 1.0 eV in agreement to the black colour. Interatomic distances obtained from the refinement of X-ray data are biased and falsified by the disorder of the SiC-dumbbell. The most evident structural parameters were obtained by relaxation calculation. Composition and carbon content were confirmed by WDX measurements. The small but significant carbon content is necessary by structural reasons and frequently caused by contaminations. The Rare Earth Compounds RE{sub 3−x}B{sub 36}Si{sub 9}C (RE=Y, Dy–Lu) are isotypic.more » Single crystals were grown from a silicon melt and their structures refined. The partial occupation of the RE-sites fits to the requirements of an electron-precise composition. According to the displacement parameters a relaxation should be applied to obtain correct structural parameters. - Graphical abstract: Single crystals of the new boridesilicide Mg{sub 3}B{sub 36}Si{sub 9}C were obtained from the elements in a Si-melt. Besides B{sub 12}-icosahedra and ethan-like Si{sub 8}-units it contains a disordered SiC-dumbbell. Correct distances were obtained by relaxation calculation based on the X-ray data. Highlights: • Black single crystals of Mg{sub 3}B{sub 36}Si{sub 9}C were yielded from the elements at 1600 °C. • The Rare Earth Compounds RE{sub 3–x}B{sub 36}Si{sub 9}C (RE=Y, Gd–Lu) are isotypic. • Correct structural parameters result from X-ray data and subsequent relaxation.« less
Gendo Oomi - One of the best experts on this subject based on the ideXlab platform.
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Effect of Pressure on the Interplay Between Orbital and Magnetic Ordering, Kondo Effect, Valence Fluctuations, and Superconductivity in Rare-Earth Compounds
Including Actinides, 2017Co-Authors: Yoshiya Uwatoko, Hiroki Takahashi, Gendo OomiAbstract:Abstract In this chapter, we present many experimental results dealing with electronic properties such as magnetic ordering or superconductivity observed at high pressure in Rare-Earth containing Compounds. We emphasize that the effect of pressure on the interplay between several interactions among conduction electrons in the Rare-Earth Compounds gives rise to anomalous behavior of the characteristic temperatures. Section 2 is dealing with pressure-induced anomalous electronic and magnetic phenomena in nonmagnetic Kondo 1-2-20 Yb and Pr Compounds, while Section 3 describes in details characteristic properties of Fe-based superconductors for materials such as (1111) and spin-ladder Compounds. The valence fluctuation phenomena under high pressure are briefly reviewed in Section 4 and different effect of the influence of pressure on the electronic properties are found for the Yb and Ce Compounds. The effects of magnetic field and pressure on the superconducting and magnetic properties are described for borocarbides showing the importance of the interplay between superconductivity and magnetism at high pressure.
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Thermal and Electronic Properties of Rare Earth Compounds at High Pressure
Handbook on the Physics and Chemistry of Rare Earths, 2012Co-Authors: Yoshiya Uwatoko, Izuru Umehara, Masashi Ohashi, Tomohito Nakano, Gendo OomiAbstract:Abstract Electronic properties of Rare Earth metals, alloys and intermetallic Compounds have attracted a lot of attention not only from the viewpoint of fundamental aspects but also from the application. These materials show a wide variety of electronic and magnetic properties, such as magnetic order, superconductivity, intermediate valence, Kondo effect and so forth. In this chapter we introduce a lot of experimental studies about the effect of pressure on the thermal, structural and electronic properties of Rare Earth Compounds, in which the electronic states are marginal due to unstable 4f electrons. We describe the present status in this research area. In section 2, the relations between crystal structure and electronic and magnetic state by using X-ray and neutron diffraction under pressure are reported. Effect of pressure on the thermal properties mainly for heavy fermions are reported in section 3. Novel pressure-induced electronic phase transitions such as the crossover in the electronic states and superconductivity are introduced for several heavy fermion materials in section 4. In the last section 5, we show miscellaneous examples which are found recently for amorphous state Rare Earth Compounds and Rare Earth magnetic multilayers.
H. Tang - One of the best experts on this subject based on the ideXlab platform.
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Magnetic properties of Rare-Earth Compounds of the type R(Fe, Ni)10Si2
Physica B: Condensed Matter, 1997Co-Authors: H. Tang, F.r. De Boer, D. Zhang, E.h. Brück, K.h.j. BuschowAbstract:The magnetic properties of Rare-Earth Compounds of the type HoFe10-xNixSi2 were investigated by means of X-ray diffraction and measurements of the magnetisation and the AC-susceptibility. It is shown that these Compounds form a complete series of solid solution in which the tetragonal ThMn12-type of structure is retained for all concentrations. From magnetic measurements made on HoNi10Si2 and GdNi10Si2, it is shown that the presence of Fe moments is essential for the occurrence of magnetic ordering above 4.2 K. For sufficiently high Fe concentration a magnetic moment is induced on the Ni atoms.
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Magnetic properties of ternary Rare Earth Compounds of the type Y(Co,Ni)10Si2
Journal of Alloys and Compounds, 1996Co-Authors: H. Tang, F.r. De Boer, E.h. Brück, K.h.j. BuschowAbstract:Abstract The magnetic properties of Rare Earth Compounds of the type YCo10−xNixSi2 were investigated by means of X-ray diffraction on magnetically aligned powders and by measurements of the temperature dependence of the magnetisation and the a.c. susceptibility. From the experimental values of the saturation magnetisation at 4.2 k, we have determined that the magnitude of the Co moments in these Compounds decreases strongly with increasing Ni content. A similar strong decrease is displayed by the corresponding Curie temperatures. We have determined the easy magnetisation direction in the various YCo10−xNixSi2 Compounds and found that the Co sublattice anisotropy favours an easy moment direction perpendicular to the c-axis and decreases with increasing Ni concentration. The results obtained have been used to explain the concentration dependence of the spin-reorientation temperature in DyCo10−xNixSi2 Compounds.
