skip to main content

Title: Phase diagram and magnetocaloric effects in Ni{sub 1-x}Cr{sub x}MnGe{sub 1.05}

The structural and magnetic properties of the Ni{sub 1−x}Cr{sub x}MnGe{sub 1.05} system (for x = 0, 0.035, 0.070, 0.105) have been studied by x-ray diffraction (XRD), differential scanning calorimetry (DSC), and magnetization measurements. A change in crystal structure from orthorhombic to hexagonal was observed in the XRD data at chromium concentrations of x = 0.035, 0.070, and 0.105. The values of the cell parameters and volume of the unit cell for orthorhombic and hexagonal phase were determined. It was found that the partial substitution of Cr for Ni in Ni{sub 1−x}Cr{sub x}MnGe{sub 1.05} results in a first order magnetostructural transition from antiferromagnetic to ferromagnetic (FM) at T{sub M} = 132 K for x = 0.105. A FM to paramagnetic second order transition has been observed at T{sub C} = 204 K. A magnetic entropy change of |ΔS{sub M}| = 4.5 J/kg K for ΔH = 5 T was observed in the vicinity of T{sub C} and T{sub M} for x = 0.105. The values of the latent heat (L = 2.2 J/g) and corresponding total entropy changes (ΔS{sub T} = 16 J/kg K) have been determined from DSC measurements. A concentration-dependent phase diagram of transition temperatures has been constructed using the magnetic and DSC data.
Authors:
; ; ; ; ;  [1] ; ;  [2]
  1. Department of Physics, Southern Illinois University, Carbondale, Illinois 62901 (United States)
  2. Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)
Publication Date:
OSTI Identifier:
22403042
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANTIFERROMAGNETISM; CALORIMETRY; CHROMIUM; CONCENTRATION RATIO; ENTROPY; GERMANIUM; INTERMETALLIC COMPOUNDS; MAGNETIC PROPERTIES; MAGNETIZATION; MANGANESE; NICKEL; ORTHORHOMBIC LATTICES; PARAMAGNETISM; PHASE DIAGRAMS; PHASE TRANSFORMATIONS; TRANSITION TEMPERATURE; X-RAY DIFFRACTION