Effects of Cr substitution on structural and magnetic properties in La{sub 0.7}Pr{sub 0.3}Fe{sub 11.4}Si{sub 1.6} compound

Journal Article · Wed May 07 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4868703· OSTI ID:22273680

Wang, J. L. ^[1]; Studer, A. J.; Kennedy, S. J. ^[2]; Gu, Q. F ^[3]; Zeng, R.; Debnath, J. C; Shamba, P.; Dou, S. X. ^[1]

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1. Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia)
2. Bragg Institute, ANSTO, Lucas Heights, NSW 2234 (Australia)
3. Australian Synchrotron, 800 Blackburn Rd, Clayton 3168 (Australia)

In an effort to explore the effect of substitution Fe by Cr in NaZn{sub 13}-type La{sub 0.7}Pr{sub 0.3}Fe{sub 11.4−x}Cr{sub x}Si{sub 1.6} (x = 0, 0.06, 0.12, 0.26, and 0.34) compounds, the structure and magnetic properties have been investigated by high intensity of x-ray and neutron diffraction, scanning electron microscopy, specific heat, and magnetization measurement. It has been found that a substitution of Cr for Fe in this compounds leads to decrease in the lattice parameter a at room temperature but variation on Curie temperature (T{sub C}). While the first order nature of magnetic phase transition around T{sub C} does not change with increasing Cr content up to x = 0.34. High intensity x-ray and neutron diffraction study at variable temperatures for highest Cr concentration x = 0.34 confirmed the presence of strong magneto-volume effect around T{sub C} and indicated the direct evident of coexistence across magnetic transition as characteristic of first order nature. The values of −ΔS{sub M} around T{sub C} decrease from 17 J kg{sup −1} K{sup −1} for x = 0 to 12 J kg{sup −1} K{sup −1} for x = 0.06 and then increases with further increasing Cr content up to 17.5 J kg{sup −1} K{sup −1} for x = 0.34 under a change of 0–5 T magnetic field. Similar behavior on relative cooling power which is decrease from 390 J kg{sup −1} for x = 0 to 365 J kg{sup −1} for x = 0.06 at the beginning and then increases up to 400 J kg{sup −1} for x = 0.34. From the point of this view with the highest Cr concentration (x = 0.34) exhibits favourable material candidate for magnetic refrigerator application therefore should inspire further study concerning on higher Cr concentration in this compound.

• OSTI ID: 22273680
• 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

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CONCENTRATION RATIO
CURIE POINT
IRON SILICIDES
LANTHANUM COMPOUNDS
LATTICE PARAMETERS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETIC REFRIGERATORS
MAGNETIZATION
NEUTRON DIFFRACTION
PHASE TRANSFORMATIONS
PRASEODYMIUM COMPOUNDS
SCANNING ELECTRON MICROSCOPY
SPECIFIC HEAT
TEMPERATURE RANGE 0273-0400 K
X-RAY DIFFRACTION