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Title: Magnetic phase transitions and entropy change in layered NdMn{sub 1.7}Cr{sub 0.3}Si{sub 2}

A giant magnetocaloric effect has been observed around the Curie temperature, T{sub C} ∼ 42 K, in NdMn{sub 1.7}Cr{sub 0.3}Si{sub 2} with no discernible thermal and magnetic hysteresis losses. Below 400 K, three magnetic phase transitions take place around 380 K, 320 K and 42 K. Detailed high resolution synchrotron and neutron powder diffraction (10–400 K) confirmed the magnetic transitions and phases as follows: T{sub N}{sup intra} ∼ 380 K denotes the transition from paramagnetism to intralayer antiferromagnetism (AFl), T{sub N}{sup inter} ∼ 320 K represents the transition from the AFl structure to the canted antiferromagnetic spin structure (AFmc), while T{sub C} ∼ 42 K denotes the first order magnetic transition from AFmc to canted ferromagnetism (Fmc + F(Nd)) due to ordering of the Mn and Nd sub-lattices. The maximum values of the magnetic entropy change and the adiabatic temperature change, around T{sub C} for a field change of 5 T are evaluated to be −ΔS{sub M}{sup max} ∼ 15.9 J kg{sup −1} K{sup −1} and ΔT{sub ad}{sup max} ∼ 5 K, respectively. The first order magnetic transition associated with the low levels of hysteresis losses (thermal <∼0.8 K; magnetic field <∼0.1 T) in NdMn{sub 1.7}Cr{sub 0.3}Si{sub 2} offers potential as a candidate for magnetic refrigerator applications in the temperature region below 45 K.
Authors:
;  [1] ;  [1] ;  [2] ;  [3] ; ; ;  [4] ;  [5] ;  [1] ;  [2]
  1. Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, New South Wales 2522 (Australia)
  2. (Australia)
  3. School of Physical, Environmental, and Mathematical Sciences, The University of New South Wales, Canberra, The Australian Defence Force Academy, Australian Capital Territory 2600 (Australia)
  4. Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234 (Australia)
  5. Australian Synchrotron, 800 Blackburn Rd, Clayton 3168 (Australia)
Publication Date:
OSTI Identifier:
22280573
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 4; Other Information: (c) 2014 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; ANTIFERROMAGNETISM; CHROMIUM SILICIDES; CURIE POINT; ENTROPY; FERROMAGNETISM; HYSTERESIS; MAGNETIC FIELDS; MAGNETIC PROPERTIES; MAGNETIC REFRIGERATORS; MANGANESE COMPOUNDS; NEODYMIUM COMPOUNDS; NEUTRON DIFFRACTION; PARAMAGNETISM; PHASE TRANSFORMATIONS; SPIN; TEMPERATURE DEPENDENCE