Magnetic Properties and Magnetocaloric Effect in Layered NdMn1.9Ti0.1Si2

M.F. Md Din (Institute of Superconducting and Electronic Material, University of Wollongong, Wollongong, NSW 2522, Australia Department Electric and Electronic Engineering, National Defence University of Malaysia, 57000 Kuala Lumpur, Malaysia)
J.L. Wang (Institute of Superconducting and Electronic Material, University of Wollongong, Wollongong, NSW 2522, Australia Bragg Institute, ANSTO, Lucas Heights, NSW 2234, Australia)
S.J. Kennedy (Bragg Institute, ANSTO, Lucas Heights, NSW 2234, Australia)
S.X. Dou (Institute of Superconducting and Electronic Material, University of Wollongong, Wollongong, NSW 2522, Australia)

Atom Indonesia Journal
Vol 40, No 1 (2014): April 2014

The structural and magnetic properties of the NdMn1.9Ti0.1Si2 compund have been studied by high-intensity x-ray and high-resolution neutron powder diffraction, specific heat, dc magnetization, and differential scanning calorimetry measurements over the temperature range of 3-450 K. The Curie temperature and Néel temperature of layered NdMn1.9Ti0.1Si2 are indicated as TC ~ 22 K and TN ~ 374 K respectively. The first order magnetic transition from antiferromagnetic [AFil-type] to ferromagnetic [F(Nd)+Fmc] around TC is found in layered NdMn1.9Ti0.1Si2and is associated with large magnetocaloric effect. This behavior has been confirmed as a contribution of the magnetostructural coupling by using neutron and x-ray powder diffraction. The magnetic entropy change –ΔSM ~ 15.3 J kg-1 K-1 and adiabatic temperature change ΔTad ~ 4.7 K have been determined using magnetization and specific heat measurement under 0-5 T applied fields. This compound exhibits almost no thermal and magnetic hysteresis, thus potentially applicable in low temperature region for magnetic refrigerator material.Received: 31 December 2013; Revised:10 February 2014; Accepted: 24 February 2014