Magnetic properties and magnetocaloric effect of NdMn{sub 2−x}Cu{sub x}Si{sub 2} compounds
- Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia)
- Bragg Institute, ANSTO, Lucas Heights, NSW 2234 (Australia)
- Australian Synchrotron, 800 Blackburn Rd, Clayton 3168 (Australia)
- School of Physical, Environmental and Mathematical Sciences, The University of New South Wales, Canberra, ACT 2600 (Australia)
Structural and magnetic properties of NdMn{sub 2−x}Cu{sub x}Si{sub 2} compounds (x = 0–1.0) have been investigated by high intensity x-ray and resolution neutron diffraction (3–450 K), specific heat, dc magnetization, and differential scanning calorimetry measurements. Substitution of Cu for Mn leads to an increase in the lattice parameter a but a decrease in c at room temperature. Two magnetic phase transitions have been found for NdMn{sub 2−x}Cu{sub x}Si{sub 2} compounds with T{sub N} for the antiferromagnetic ordering of Mn-sublatttice and T{sub C} for the Nd-sublattice ferromagnetic ordering, respectively. T{sub C} increases significantly with increasing Cu content from 36 K at x = 0 to 100 K at x = 1.0. Moreover, it is found that the order of magnetic phase transition around T{sub C} also changes from first order at x < 0.6 to second order transition for x ≥ 0.6. The spontaneous magnetization found to decrease with the increase in Cu concentration which can be understood in the term of the dilution effect of Cu for Mn. The values of −ΔS{sub M} around T{sub C} decrease with increasing x from 27 J kg{sup −1} K{sup −1} for x = 0 to 0.5 J kg{sup −1} K{sup −1} for x = 1.0 under 0–5 T field. Refinement of neutron diffraction patterns for x = 0.2 confirms the magnetic states detected by magnetic study and also indicates that the lattice constants a and c show a distinct variation around T{sub C}.
- OSTI ID:
- 22273809
- Journal Information:
- Journal of Applied Physics, Vol. 115, Issue 17; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETISM
CALORIMETRY
CONCENTRATION RATIO
COPPER COMPOUNDS
DIFFERENTIAL THERMAL ANALYSIS
LATTICE PARAMETERS
MAGNETIC PROPERTIES
MAGNETIZATION
MANGANESE SILICIDES
NEEL TEMPERATURE
NEODYMIUM COMPOUNDS
NEUTRON DIFFRACTION
PHASE TRANSFORMATIONS
SPECIFIC HEAT
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
X-RAY DIFFRACTION