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Title: Phase transitions and magnetocaloric and transport properties in off-stoichiometric GdNi 2Mn x

Here, the structural, magnetic, magnetocaloric, transport, and magnetoresistance properties of the rare-earth intermetallic compounds GdNi 2Mn x (0.5 ≤ x ≤ 1.5) have been studied. The compounds with x = 0.5 and 0.6 crystallize in the cubic MgCu 2 type phase, whereas samples with x ≥ 0.8 form a mixed MgCu 2 and rhombohedral PuNi 3 phase. A second order magnetic phase transition from a ferromagnetic to paramagnetic state was observed near the Curie temperature (T C). The GdNi 2Mn x (0.5 ≤ x ≤ 1.5) compounds order in a ferrimagnetic structure in the ground state. The largest observed values of magnetic entropy changes (at T C for ΔH = 5T) were 3.9, 3.5, and 3.1 J/kg K for x = 0.5, 0.6, and 0.8, respectively. The respective relative values of the cooling power were 395, 483, and 220 J/kg. These values are greater than some well-known prototype magnetocaloric materials such as Gd (400 J/kg) and Gd 5Si 2Ge 2 (240 J/kg). Analysis of the resistivity data showed a T 2 dependence at low temperatures, suggesting strong electron-phonon interactions, whereas at higher temperatures s-d scattering was dominated by the electron-phonon contribution, resulting in a slow increase in resistivity. Magnetoresistance valuesmore » of ~–1.1% were found for x = 0.5 near T C, and –7% for x = 1.5 near T = 80 K.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [2] ;  [1]
  1. Southern Illinois Univ. Carbondale, IL (United States)
  2. Louisiana State Univ., Baton Rouge, LA (United States)
Publication Date:
Grant/Contract Number:
FG02-06ER46291; FG02-13ER46946
Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 119; Journal Issue: 4; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Research Org:
Southern Illinois Univ., Carbondale, IN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
OSTI Identifier:
1469195
Alternate Identifier(s):
OSTI ID: 1236398