scholarly journals Entropy of Conduction Electrons from Transport Experiments

Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 244
Author(s):  
Nicolás Pérez ◽  
Constantin Wolf ◽  
Alexander Kunzmann ◽  
Jens Freudenberger ◽  
Maria Krautz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Phase ◽  
Entropy Change ◽  
Magnetic Phase Transitions ◽  
Disordered Materials ◽  
Conduction Electrons ◽  
Alloy Series ◽  
Definition Of ◽  
Scientific Questions ◽  
Electronic Entropy

The entropy of conduction electrons was evaluated utilizing the thermodynamic definition of the Seebeck coefficient as a tool. This analysis was applied to two different kinds of scientific questions that can—if at all—be only partially addressed by other methods. These are the field-dependence of meta-magnetic phase transitions and the electronic structure in strongly disordered materials, such as alloys. We showed that the electronic entropy change in meta-magnetic transitions is not constant with the applied magnetic field, as is usually assumed. Furthermore, we traced the evolution of the electronic entropy with respect to the chemical composition of an alloy series. Insights about the strength and kind of interactions appearing in the exemplary materials can be identified in the experiments.

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.

scholarly journals Large entropy change accompanying two successive magnetic phase transitions in TbMn2Si2 for magnetic refrigeration

2015 ◽  
Vol 106 (18) ◽  
pp. 182405 ◽  
Author(s):  
Guoxing Li ◽  
Jianli Wang ◽  
Zhenxiang Cheng ◽  
Qingyong Ren ◽  
Chunsheng Fang ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Magnetic Phase ◽  
Entropy Change ◽  
Magnetic Refrigeration ◽  
Magnetic Phase Transitions

scholarly journals Magnetic phase transitions and magnetic entropy in the XY antiferromagnetic pyrochlores (Er 1− x Y x ) 2 Ti 2 O 7

2014 ◽  
Vol 470 (2171) ◽  
pp. 20140387 ◽  
Author(s):  
John F. Niven ◽  
Michel B. Johnson ◽  
Alex Bourque ◽  
Patrick J. Murray ◽  
David D. James ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
Magnetic Phase ◽  
Magnetic Phase Transitions ◽  
Magnetic Contribution ◽  
Magnetic Entropy ◽  
Lattice Contribution ◽  
Lower Temperature ◽  
Very High

We present the results of experimental determination of the heat capacity of the pyrochlore Er 2 Ti 2 O 7 as a function of temperature (0.35–300 K) and magnetic field (up to 9 T), and for magnetically diluted solid solutions of the general formula (Er 1− x Y x ) 2 Ti 2 O 7 ( x ≤0.471). On either doping or increase of magnetic field, or both, the Néel temperature first shifts to lower temperature until a critical point above which there is no well-defined transition but a Schottky-like anomaly associated with the splitting of the ground state Kramers doublet. By taking into account details of the lattice contribution to the heat capacity, we accurately isolate the magnetic contribution to the heat capacity and hence to the entropy. For pure Er 2 Ti 2 O 7 and for (Er 1− x Y x ) 2 Ti 2 O 7 , the magnetic entropy as a function of temperature evolves with two plateaus: the first at R ln ⁡ 2 , and the other at R ln ⁡ 16 . When a very high magnetic field is applied, the first plateau is washed out. The influence of dilution at low values is similar to the increase of magnetic field, as we show by examination of the critical temperature versus critical field curve in reduced terms.

scholarly journals Магнитоструктурные особенности фазовых переходов в системе Mn-=SUB=-1-x-=/SUB=-Co-=SUB=-x-=/SUB=-NiGe Часть 1. Экспериментальные результаты

2021 ◽  
Vol 63 (12) ◽  
pp. 2073
Author(s):  
В.И. Митюк ◽  
Г.С. Римский ◽  
К.И. Янушкевич ◽  
В.В. Коледов ◽  
А.В. Маширов ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Phase ◽  
Experimental Studies ◽  
Anomalous Behavior ◽  
Magnetic Phase Transitions ◽  
Strong Magnetic Fields ◽  
Weak Magnetic Fields ◽  
Wide Range ◽  
Co Concentrations

Experimental studies of the magnetic and structural properties of solid solutions of the Mn1-xCoxNiGe system in a wide range of Co concentrations (0.05≤ x≤ 0.8), temperatures (5 K≤ x≤600 K) and magnetic fields (0.016 T≤ x≤ 13.5 T) have revealed a number of nontrivial magnetic and magnetocaloric features of this system. The latter include: 1) a change in the nature of magnetic phase transitions from magnetostructural transitions of the 1st order paramagnetism-antiferromagnetism (0.05≤ x≤ 0.15) to isostructural transitions of the 2nd order paramagnetism-ferromagnetism (0.15≤ x≤0.8) with a change in the concentration of Co ; 2) anomalous behavior of low-temperature regions of magnetization in weak magnetic fields; 3) a change in the saturation magnetization and the appearance of irreversible magnetic field-induced transitions at helium temperatures in strong magnetic fields.

Magnetic phase transitions of CeSb. I. Zero applied magnetic field

1978 ◽  
Vol 11 (2) ◽  
pp. 345-364 ◽  
Author(s):  
P Fischer ◽  
G Meier ◽  
B Lebech ◽  
B D Rainford ◽  
O Vogt
Keyword(s):  
Magnetic Field ◽  
Phase Transitions ◽  
Applied Magnetic Field ◽  
Magnetic Phase ◽  
Magnetic Phase Transitions

Large magnetic entropy change in compound LaFe/sub 11.44/Al/sub 1.56/ with two magnetic phase transitions

2001 ◽  
Vol 37 (4) ◽  
pp. 2328-2330 ◽  
Author(s):  
Feng-Xia Hu ◽  
Bao-Gen Shen ◽  
Ji-Rong Sun ◽  
A.B. Pakhomov ◽  
C.Y. Wong ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Magnetic Entropy Change ◽  
Magnetic Phase ◽  
Entropy Change ◽  
Magnetic Phase Transitions ◽  
Magnetic Entropy
Sign in / Sign up

Export Citation Format

Share Document