Modification of magnetic ground state in Tb2Ni0. 90Si2. 94 by thermal annealing
No Thumbnail Available
Date
2020-09-01
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
In this work, we have investigated the thermal annealing effect on the physical properties of an AlB-type ternary intermetallic compound, TbNi0.90Si2.94, that undergoes spin freezing behaviour coexisting with spatially limited antiferromagnetic phase below 9.9 K in as-cast form. Thermal annealing effect is found to result in considerable changes in the magnetic ground state properties of the system. Though only one magnetic transition around 9.9 K is observed for as-cast compound, the annealed sample exhibits two distinct magnetic transitions; one around 13.5 K and another around 4 K. The magnetization measurements and zero field neutron diffraction study reveal that the high temperature transition is antiferromagnetic type, though of limited correlation length, while the low temperature transition corresponds to spin freezing behaviour. The ac susceptibility and heat capacity studies also confirm the existence of frustrated cluster glass state at lower temperature than the antiferromagnetic ordering temperature. Additionally, ac susceptibility data exhibits signature of an additional peak in the even lower temperature region (at 2.2 K for zero frequency) that tends to shift in opposite direction with frequency in contrast to that observed for conventional glassy transitions. The change in intrinsic local structural disorder of Ni and Si ions associated with annealing has been argued to be responsible for the different magnetic behaviour in as-cast and annealed samples. Published by Elsevier Ltd.
Description
Keywords
X-ray diffraction, Antiferromagnetism, Spin, Magnetization, Annealing, Silicon, Terbium, Intermetallic compounds, Nickel alloys
Citation
Pakhira, S., Bhowmik, R. N., Avdeev, M., Ranganathan, R., & Mazumdar, C. (2020) Modification of magnetic ground state in Tb2Ni0.90Si2.94 by thermal annealing. Intermetallics, 124, 106874. doi:10.1016/j.intermet.2020.106874