scholarly journals On the magnetocaloric effect of itinerant electron systems with first order transition

2013 ◽  
Vol 392 (6) ◽  
pp. 1355-1360 ◽  
Author(s):  
L.G. de Medeiros ◽  
N.A. de Oliveira ◽  
P.J. von Ranke ◽  
A. Troper
Keyword(s):  
Magnetocaloric Effect ◽  
Order Transition ◽  
Itinerant Electron ◽  
Electron Systems ◽  
First Order ◽  
First Order Transition

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.

scholarly journals Large Low-Field Reversible Magnetocaloric Effect in Itinerant-Electron Hf1-xTaxFe2 Alloys

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5233
Author(s):  
Zhao Song ◽  
Zongbin Li ◽  
Bo Yang ◽  
Haile Yan ◽  
Claude Esling ◽  
...  
Keyword(s):  
Magnetocaloric Effect ◽  
High Performance ◽  
Thermal Hysteresis ◽  
Second Order ◽  
Order Transition ◽  
Itinerant Electron ◽  
First Order ◽  
Second Order Transition ◽  
Magnetic Field Change ◽  
Materials Used

First-order isostructural magnetoelastic transition with large magnetization difference and controllable thermal hysteresis are highly desirable in the development of high-performance magnetocaloric materials used for energy-efficient and environmental-friendly magnetic refrigeration. Here, we demonstrate large magnetocaloric effect covering the temperature range from 325 K to 245 K in Laves phase Hf1-xTaxFe2 (x = 0.13, 0.14, 0.15, 0.16) alloys undergoing the magnetoelastic transition from antiferromagnetic (AFM) state to ferromagnetic (FM) state on decreasing the temperature. It is shown that with the increase of Ta content, the nature of AFM to FM transition is gradually changed from second-order to first-order. Based on the direct measurements, large reversible adiabatic temperature change (ΔTad) values of 2.7 K and 3.4 K have been achieved under a low magnetic field change of 1.5 T in the Hf0.85Ta0.15Fe2 and Hf0.84Ta0.16Fe2 alloys with the first-order magnetoelastic transition, respectively. Such remarkable magnetocaloric response is attributed to the rather low thermal hysteresis upon the transition as these two alloys are close to intermediate composition point of second-order transition converting to first-order transition.

scholarly journals First Order Transition for the Optimal Search Time of Lévy Flights with Resetting

2014 ◽  
Vol 113 (22) ◽  
Author(s):  
Lukasz Kusmierz ◽  
Satya N. Majumdar ◽  
Sanjib Sabhapandit ◽  
Grégory Schehr
Keyword(s):  
Search Time ◽  
Order Transition ◽  
Optimal Search ◽  
Lévy Flights ◽  
First Order ◽  
Levy Flights ◽  
First Order Transition

Fluctuation-induced first-order transition in the Hubbard model

1990 ◽  
Vol 74 (11) ◽  
pp. 1175-1179 ◽  
Author(s):  
M.D. Coutinho-Filho ◽  
M.L. Lyra ◽  
A.M. Nemirovsky
Keyword(s):  
Hubbard Model ◽  
Order Transition ◽  
First Order ◽  
First Order Transition
Sign in / Sign up

Export Citation Format

Share Document