Complex magnetic behaviour and evidence of superspin glass state in a binary intermetallic compound Er5Pd2

A binary intermetallic compound Er5Pd2 has been investigated using dc and ac magnetic susceptibilities, magnetic memory effect, isothermal magnetization, non-linear dc susceptibility, heat capacity and magnetocaloric effect studies. Interestingly, even though the compound does not show geometrical frustration it undergoes glassy magnetic phase transition below 17.2 K. Investigation of dc magnetisation and heat capacity data divulged absence of long-ranged magnetic ordering. Through magnetic memory effect, time dependent magnetization and ac susceptibility studies it was revealed that the compound undergoes glass-like freezing below 17.2 K. Analysis of frequency dependence of this transition temperature through scaling and Arrhenius law; along with Mydosh parameter indicate, that the dynamics in Er5Pd2 is due to the presence of strongly interacting superspins rather than individual spins. This phase transition was further investigated by non-linear dc susceptibility and was characterized by static critical exponents {\gamma} and {\delta}. Our results indicate that this compound show signature of superspin glass at low temperature. Additionally, both conventional and inverse magnetocaloric effect was observed with large value of magnetic entropy change and relative cooling power. Our results suggest that Er5Pd2 can be classified as a superspin glass system with large magnetocaloric effect.

Mohit K. Sharma, Kavita Yadav, K. Mukherjee · 2017