The effect of temperature span of the first-order transition processes on magnetic entropy change in NiMnGa alloys

2007 ◽  
Vol 432 (1-2) ◽  
pp. 45-48 ◽  
Author(s):  
Jingfang Duan ◽  
Peng Huang ◽  
Hu Zhang ◽  
Yi Long ◽  
Guangheng Wu ◽  
...  
Keyword(s):  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Order Transition ◽  
Effect Of Temperature ◽  
Magnetic Entropy ◽  
Transition Processes ◽  
First Order ◽  
First Order Transition

Magnetic Phase Transitions and Magnetocaloric Properties of Gd5Si0.4In3.6 Compound

2013 ◽  
Vol 320 ◽  
pp. 67-71
Author(s):  
Chao Jing ◽  
X.L. Wang ◽  
D.H. Yu ◽  
Y.J. Yang ◽  
B.J. Kang ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Magnetic Entropy Change ◽  
Magnetic Phase ◽  
Entropy Change ◽  
Ferromagnetic State ◽  
Order Transition ◽  
Magnetic Phase Transitions ◽  
Magnetocaloric Properties ◽  
Second Order Transition ◽  
First Order Transition

The magnetic phase transitions and magnetocaloric properties of Gd5Si0.4In3.6 compound have been investigated. Magnetothermal measurements performed at different conditions reveal that the sample undergoes two magnetic phase transitions. One is a second-order transition from paramagnetic to ferromagnetic state at about 197 K, the other is a first-order transition when the temperature is reduced to 75 K. The magnetocaloric effect around Curie temperature (TC) was calculated in terms of isothermal magnetic entropy change by using Maxwells equation,which remains over a quite wide temperature span of 70 K between the temperature region from160 to 240 K, and thus makes this material attractive for magnetic refrigerator applications.

On the determination of the magnetic entropy change in materials with first-order transitions

2009 ◽  
Vol 321 (21) ◽  
pp. 3559-3566 ◽  
Author(s):  
L. Caron ◽  
Z.Q. Ou ◽  
T.T. Nguyen ◽  
D.T. Cam Thanh ◽  
O. Tegus ◽  
...  
Keyword(s):  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
First Order

Broad first-order magnetic entropy change curve in directionally solidified polycrystalline Ni-Co-Mn-In

2017 ◽  
Vol 727 ◽  
pp. 603-609 ◽  
Author(s):  
F. Chen ◽  
Y.X. Tong ◽  
L. Li ◽  
J.L. Sánchez Llamazares ◽  
C.F. Sánchez-Valdés ◽  
...  
Keyword(s):  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Directionally Solidified ◽  
First Order ◽  
Change Curve

Comparative Study of the Magnetocaloric Properties in Ni-Mn-X (X = Ga, In, Sn) by Magnetization and Specific Heat Measurements

2009 ◽  
Vol 1200 ◽  
Author(s):  
V V Khovaylo ◽  
K P Skokov ◽  
E V Avilova ◽  
Val Novosad ◽  
H Miki ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Ferromagnetic Shape Memory Alloys ◽  
First Order ◽  
Magnetocaloric Properties ◽  
Heat Capacity Measurements ◽  
Capacity Data ◽  
Ferromagnetic Shape Memory

AbstractSome compositions of Ni-Mn-X (X = Ga, In, Sn) ferromagnetic shape memory alloys exhibit a first order magnetostructural phase transition. Magnetic entropy change ΔSm in the vicinity of this transition has been studied by magnetization and heat capacity measurements. Comparison of these results point to a large difference in magnitudes of ΔSm obtained from magnetization and heat capacity data. It is suggested that this discrepancy originates from overestimation of \Delta S_m determined from the magnetization measurements and underestimation of ΔSm obtained from the heat capacity measurements.

Study of Magnetocaloric Properties of Ni-Mn-X (X = Ga, In) Heusler Alloys by Monte Carlo Technique

2009 ◽  
Vol 1200 ◽  
Author(s):  
Vasiliy Buchelnikov ◽  
Vladimir Sokolovskiy ◽  
Sergey Taskaev ◽  
Peter Entel
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Monte Carlo ◽  
Magnetic Entropy Change ◽  
Heusler Alloys ◽  
Entropy Change ◽  
Magnetic Contribution ◽  
Magnetic Entropy ◽  
First Order ◽  
Magnetocaloric Properties

AbstractTwo theoretical Monte Carlo models have been presented for description of the positive and negative magnetocaloric effects of Heusler Ni-Mn-X (X = Ga, In) alloys undergoing first order coupled magnetostructural phase transition. For both models all quantities such as temperature dependence of the magnetic contribution to the total specific heat, magnetization and isothermal magnetic entropy change are in qualitative agreement with the available experimental data.

scholarly journals Origin of Hysteresis in La0.67Ca0.33MnO3

2011 ◽  
Vol 1310 ◽  
Author(s):  
K. Morrison ◽  
A. Berenov ◽  
LF Cohen
Keyword(s):  
Entropy Change ◽  
Order Transition ◽  
Cooling Cycle ◽  
First Order ◽  
Magnetocaloric Materials ◽  
First Order Transition

ABSTRACTHysteresis is unattractive for magnetocaloric applications because it introduces loss in the cooling cycle. It is however usually associated with a first order transition and large entropy change. In this paper we review the sources of hysteresis in magnetocaloric materials and in particular in manganite systems where the nature of the transition in terms of whether it is indeed a first order transition remains elusive.

Magnetic Phase Transition and Magnetic Proporties of LaFe11.6Si1.4Bx Compounds

2013 ◽  
Vol 750-752 ◽  
pp. 919-922
Author(s):  
Kun Xie ◽  
Yin Liu ◽  
Mei Qing Cao ◽  
Peng Cheng Xia ◽  
Li Jie Yue
Keyword(s):  
Phase Transition ◽  
Curie Temperature ◽  
Magnetic Phase Transition ◽  
Magnetic Entropy Change ◽  
Magnetic Phase ◽  
Magnetic Transition ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
First Order ◽  
Melt Spun

The magnetic phase transition and magnetic entropy change of melt-spun LaFe11.6Si1.4Bx(x=0.0, 0.3, 0.5, 0.7) ribbons were investigated by measuring the magnetization as the function of temperature. Comparing with LaFe11.6Si1.4, the NaZn13-type structure of LaFe11.6Si1.4Bxdid not change after introducing B atoms, while the amount of α-Fe phase in the ribbons significantly decreased. The Curie temperature slightly changes after the addition of B. The LaFe11.6Si1.4Bx(x=0.3, 0.5) exhibits first-order magnetic transition and large magnetic entropy change as observed in LaFe11.6Si1.4compound.

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