FIRST-ORDER MAGNETIC PHASE TRANSITIONS AND COLOSSAL MAGNETORESISTANCE: JOINING MANGANESE PEROVSKITES AND MnAs

2004 ◽  
Vol 18 (15) ◽  
pp. 725-747 ◽  
Author(s):  
J. MIRA ◽  
J. RIVAS
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Magnetic Phase Transition ◽  
Colossal Magnetoresistance ◽  
Magnetic Phase ◽  
Magnetic Phase Transitions ◽  
Colossal Magnetoresistive ◽  
First Order ◽  
First Order Transition ◽  
Magnetoresistive Effect

We revise some recent results on the nature of the magnetic phase transition of ferromagnetic manganese perovskites with colossal magnetoresistance. It is found that they exhibit first-order magnetic phase transitions mainly due to strong lattice effects. The presence of such first-order transition is strongly linked to the existence of a temperature region above the Curie Temperature with a phase-separated regime of coexisting metallic and insulating clusters. This situation is compared with that of MnAs , paradigm of system with first-order magnetic phase transition, and we observe a parallel phenomenology of these apparently different systems. This serves as a clue for the finding of a phase-separated regime also in MnAs and, moreover, for the finding of a colossal magnetoresistive effect similar to that of manganese perovskites.

MAGNETIC PHASE TRANSITIONS IN Ce(Fe1–xCox)2 SYSTEM

1993 ◽  
Vol 07 (01n03) ◽  
pp. 822-825 ◽  
Author(s):  
NAUSHAD ALI ◽  
XIANFENG ZHANG
Keyword(s):  
Phase Transitions ◽  
Magnetic Phase ◽  
Ac Susceptibility ◽  
Magnetic Phase Diagram ◽  
Ferromagnetic State ◽  
Magnetic Phase Transitions ◽  
Itinerant Electron ◽  
Electron Systems ◽  
First Order ◽  
First Order Transition

Re-entrant magnetic phase transitions in Ce(Fe1–xMx)2 systems (where M=Al, Ru, Co, etc.) are being investigated by various research groups. It has been observed that the system goes from a paramagnetic to ferromagnetic state followed by an almost complete loss of magnetization as the temperature is lowered. We have done systematic experimental measurements of magnetization, ac susceptibility, electrical resistivity, and thermal expansion on the Ce(Fe1–xCox)2 system. It is found that as the temperature is decreased, the system goes from para- to ferro- to antiferro-magnetic phase. The ferro- to antiferro-magnetic phase transition is a first order transition. Our experimental results are consistent with the magnetic phase diagram predictions by Moriya and Usami's theory of strongly interacting itinerant electron systems.

First-order magnetic phase transition in layered Sr3YCo4O10.5 + δ-type cobaltites

JETP Letters ◽  
2012 ◽  
Vol 94 (12) ◽  
pp. 849-852 ◽  
Author(s):  
I. O. Troyanchuk ◽  
M. V. Bushinsky ◽  
V. M. Dobryanskii ◽  
N. V. Pushkarev
Keyword(s):  
Phase Transition ◽  
Magnetic Phase Transition ◽  
Magnetic Phase ◽  
First Order ◽  
Order Magnetic Phase Transition

Verification of first‐order magnetic phase transition in single crystal iron films

1982 ◽  
Vol 53 (11) ◽  
pp. 7966-7968 ◽  
Author(s):  
F. J. Rachford ◽  
G. A. Prinz ◽  
J. J. Krebs ◽  
K. B. Hathaway
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Magnetic Phase Transition ◽  
Magnetic Phase ◽  
Iron Films ◽  
First Order ◽  
Order Magnetic Phase 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.

First-order magnetic phase transition in PrCo9Si4 and NdCo9Si4

2004 ◽  
Vol 272-276 ◽  
pp. E445-E447 ◽  
Author(s):  
M El-Hagary ◽  
H Michor ◽  
E Bauer ◽  
M Della Mea ◽  
K Hense ◽  
...  
Keyword(s):  
Phase Transition ◽  
Magnetic Phase Transition ◽  
Magnetic Phase ◽  
First Order ◽  
Order Magnetic Phase Transition
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