skip to main content

Title: Magnetocaloric effect and magnetostructural coupling in Mn{sub 0.92}Fe{sub 0.08}CoGe compound

The structural properties of Mn{sub 0.92}Fe{sub 0.08}CoGe have been investigated in detail using synchrotron x-ray diffraction in zero and applied pressure (p = 0–10 GPa). A ferromagnetic transition occurs around T{sub C} = 300 K and a large magnetic-entropy change −ΔS{sub M} = 17.3 J/kg K detected at T{sub C} for a field change of ΔB = 5 T. The field dependence of −ΔS{sub M}{sup max} can be expressed as −ΔS{sub M}{sup max} ∝ B. At ambient temperature and pressure, Mn{sub 0.92}Fe{sub 0.08}CoGe exhibits a co-existence of the orthorhombic TiNiSi-type structure (space group Pnma) and hexagonal Ni{sub 2}In-type structure (space group P63/mmc). Application of external pressure drives a structure change from the orthorhombic TiNiSi-type structure to the hexagonal Ni{sub 2}In-type structure. A large anomaly in heat capacity around T{sub C} is detected and the Debye temperature θ{sub D} (=319(±10) K) has been derived from analyses of the low temperature heat capacity, T ≲ 10 K.
Authors:
 [1] ;  [2] ; ; ; ;  [1] ; ; ;  [3] ;  [4] ;  [5]
  1. Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia)
  2. (Australia)
  3. School of Physical, Environmental and Mathematical Sciences, The University of New South Wales, Canberra, ACT 2600 (Australia)
  4. Australian Synchrotron, 800 Blackburn Rd, Clayton 3168 (Australia)
  5. Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, NSW 2234 (Australia)
Publication Date:
OSTI Identifier:
22410051
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; AMBIENT TEMPERATURE; COBALT COMPOUNDS; COUPLING; DEBYE TEMPERATURE; ENTROPY; FERROMAGNETISM; GERMANIDES; HEXAGONAL LATTICES; IRON COMPOUNDS; MAGNETIC PROPERTIES; MANGANESE COMPOUNDS; ORTHORHOMBIC LATTICES; PRESSURE DEPENDENCE; PRESSURE RANGE GIGA PA; SPECIFIC HEAT; TEMPERATURE DEPENDENCE; X-RAY DIFFRACTION