Electron Magnetic Resonance Studies of the Intercalation Ferromagnet 2,2′-bipyridine-MnPS3 Above and Below Curie Temperature

Abstract

Electron magnetic resonance (EMR) studies of intercalation ferromagnet 2,2′-bipyridine-MnPS3 (Tc = 40 K) in the temperature range 300 – 14 K have revealed many interesting features across the (magnetic) order ← → disorder transition. The exchange narrowed line in the paramagnetic phase exhibited sudden reduction in its intensity concomitant with a g-shift to lower values (line shifted to higher fields) and increased line width. These changes took place in the 40–25 K range. In the 25–22K range of temperature, the paramagnetic line disappeared and the FMR signal appeared at lower fields. It is significant that two closely lying FMR signals appeared in the magnetically ordered regime, suggesting the possibility of existence of two different Mn-sites having different g-values, in this state. This may be responsible for the reported magnetic moments values of less than 5.98 BM from bulk magnetisation studies.