Crystal and magnetic properties of 57Fe doped MnAs for magnetic refrigeration application

• Published in: Journal of the Korean Physical Society Vol. 71; no. 9; pp. 575 - 578
• Main Authors: Lim, Jung Tae, Cho, Hyun Tae, Kim, Sam Jin, Kim, Chul Sung, Lee, Young Bae
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.11.2017; Springer Nature B.V; 한국물리학회
• Subjects: Chemical synthesis; Crystallography; Curie temperature; Diffraction; Magnetic properties; Magnetism; Magnetization; Magnetization curves; Mathematical and Computational Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Refrigeration; Superconducting quantum interference devices; Superconductivity; Theoretical; 물리학; Magnetocaloric effect; Mössbauer spectroscopy; MnAs
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.71.575

The Mn 1− x 57 Fe x As ( x = 0.001, 0.003, 0.005) compounds for magnetic refrigeration application were synthesized by using a solid-vapor reaction method. We have investigated the crystallographic and magnetic properties of Mn 1− x 57 Fe x As ( x = 0.001, 0.003, 0.005) samples by using x-ray diffractometer (XRD), vibrating sample magnetometer (VSM), superconducting quantum interference device (SQUID), and Mössbauer spectrometer. The XRD patterns, revealed that all samples exhibited hexagonal space group P 6 3 / mmc below Curie temperature ( T C ), while above T C they belong to the orthorhombic space group Pnma . The temperature-dependent magnetization curves under 200 Oe between 4.2 and 320 K showed a large hysteresis in the magnetization as a function of the temperature. To analyze the meagnetocaloric effect, the value of magnetic entropy (−Δ S M ) was calculated from the isothermal initial curves up to 5 T at various temperatures. Mössbauer spectra of Mn 0.997 57 Fe 0.003 As sample were taken at various temperatures ranging from 4.2 to 315 K.