Results 251 to 260 of about 28,460 (303)

Magnetic-entropy change in Mn1.1Fe0.9P0.7As0.3–xGex

Journal of Alloys and Compounds, 2005
Abstract We have studied the magnetic properties and magnetic-entropy changes of Mn1.1Fe0.9P0.7As0.3–xGex compounds with x = 0, 0.05, 0.1, 0.15 and 0.3. X-ray diffraction (XRD) study shows all the compounds crystallize in the Fe2P-type structure. Magnetic measurements show that the Curie temperature increases from 150 K for Mn1.1Fe0.9P0.7As0.3 to 380 
Tegus, O., Fuquan, B., Dagula, D., Zhang, L., Brück, E.H., Si, P., de Boer, F.R., Buschow, K.H.J.   +7 more
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Large magnetic entropy change above 300 K in (La0.56Ce0.14)Sr0.3MnO3 perovskite

Journal of Alloys and Compounds, 2010
International audienceMagnetic field dependence of the magnetic entropy change (ΔSM) is the key for magnetic refrigeration. A large magnetic entropy change (ΔSM) associated with the ferromagnetic-paramagnetic transition in Ce-doped La0.7Sr0.3MnO3 ...
Nabil Kallel, Octavio Pena, Mohamed Oumezzine   +2 more
exaly   +2 more sources

Magnetic entropy change of magnetic fluids

Physica B: Condensed Matter, 2002
Abstract Magnetization measurements of Co-, Fe-, and Fe3O4-based magnetic fluids were carried out in the temperature range 85 K T  K and in magnetic fields up to 8 kOe. The magnetic entropy change, ΔS(H,T), was calculated for each sample using the relevant thermodynamic Maxwell relation.
I. Abu-Aljarayesh, A.F. Al-Jamel, M.R. Said   +2 more
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Magnetic entropy change in La0.67−Ca0.33MnO3

Journal of Alloys and Compounds, 2004
Abstract Polycrystalline samples of La0.67−xCa0.33MnO3 (x=0.00, 0.02, 0.06, and 0.10) with different La site vacancies have been prepared by the sol–gel method. The grain sizes of the samples are observed by SEM. XRD results show that the samples are single phase of perovskite-type oxides.
D.L. Hou, Y. Bai, J. Xu, G.D. Tang, X.F. Nie   +4 more
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Magnetic entropy change in La0.54Ca0.32MnO3−δ

Journal of Applied Physics, 2001
A La-deficient manganite perovskite sample La0.54Ca0.32MnO3−δ was prepared by conventional solid-state reaction method. The Curie temperature TC is 272 K, about 10 K higher than that of La1−xCaxMnO3. A large magnetic entropy change has been observed and the maximum −ΔSM≈2.9 J/kg K appears at its Curie temperature upon a 0.9 T magnetic field change. The
Q. Y. Xu, K. M. Gu, X. L. Liang, G. Ni, Z. M. Wang, H. Sang, Y. W. Du   +6 more
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Magnetic transition and magnetic entropy changes of La0.8Pb0.1MnO3 and La0.8Pb0.1Na0.1MnO3

Materials Letters, 2010
Abstract In the present work we analyze the magnetic entropy change ΔSM of La0.8Pb0.1MnO3 (LPMO) and La0.8Pb0.1Na0.1MnO3 (LPNMO). Using Arrott plots, it was found that the phase transition for both samples is of second-order. The presence of short-range magnetic order (SRMO) in the paramagnetic phase of these samples greatly depresses the magnetic ...
A. Tozri, E. Dhahri, E.K. Hlil
openaire   +1 more source

Magnetic properties and magnetic entropy changes of MRE2Co7 compounds

Science China Physics, Mechanics & Astronomy, 2015
(La0.5Ce0.5)2Co7 and (Ce0.65Pr0.35)2Co7 compounds for magnetic refrigeration were studied by X-ray diffraction, ac susceptibility and isothermal magnetization measurements. X-ray powder diffraction shows that all the compounds have hexagonal Ce2Ni7-type structure. The Curie temperatures (T C
XiChun Zhong, ZhongWu Liu, JiXiong Min, HuaCun Tian, Karl A. Gschneidner, Vitalij K. Pecharsky   +5 more
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Magnetic field dependence of the maximum magnetic entropy change

Physical Review B, 2011
The maximum isothermal entropy change in a magnetic refrigerant with a second-order phase transition is shown to depend on applied magnetic field $H$ as follows: $(\ensuremath{-}\ensuremath{\Delta}S){}_{\mathrm{max}}$ $=$ $A$($H$ $+$ ${H}_{0}$)${}^{2/3}$ -- ${\mathit{AH}}_{0}^{2/3}$ $+$ $\mathit{BH}$${}^{4/3}$. Here $A$ and $B$ are intrinsic parameters
Lyubina, Julia, Kuz'min, Michael, Schlagel, Deborah, Nenkov, Konstantin, Gutfleisch, Oliver, Richter, Manuel, Lograsso, Thomas, Gschneidner, Karl   +7 more
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Magnetic properties and magnetic entropy change of Co50Ni22Ga28 alloy

Journal of Alloys and Compounds, 2009
Abstract Heusler-type alloy Co 50 Ni 22 Ga 28 was synthesized by arc-melting. X-ray diffraction (XRD) results show that the as-cast Co 50 Ni 22 Ga 28 alloy consists of a main phase of body-centered tetragonal martensite β and a little fcc γ phase. The austenitic–martensitic phase transformation was confirmed by DSC, which agreed with corresponding ...
H. Fu, H.J. Yu, B.H. Teng, X.Y. Zhang, X.T. Zu   +4 more
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Magnetic entropy change in core/shell and hollow nanoparticles

Journal of Physics: Condensed Matter, 2013
The development of positive magnetic entropy change in the case of ferromagnetic (FM) nanostructures is a rare occurrence. We observe positive magnetic entropy change in core/shell (Fe/γ-Fe2O3) and hollow (γ-Fe2O3) nanoparticles and its origin is attributed to a disordered state in the nanoparticles due to the random distribution of anisotropy axes ...
Sayan, Chandra, Anis, Biswas, Hafsa, Khurshid, Wanfeng, Li, G C, Hadjipanayis, Hariharan, Srikanth   +5 more
openaire   +2 more sources