LAUSR

Abstract We report the structural and magnetic properties of a new system LiRhMnO 4 (LRMO) through X-ray diffraction, bulk magnetization, heat capacity and 7Li nuclear magnetic resonance (NMR) measurements. LRMO crystallizes in the cubic space group Fd 3 ¯ m . From the DC susceptibility data, we obtained the Curie-Weiss temperature θ CW  = −26 K and Curie constant C  = 1.79  Kcm 3 / mol suggesting antiferromagnetic correlations among the magnetic Mn 4 + ions with an effective spin S = 3 2 . At H  = 50 Oe, the field cooled and zero-field cooled magnetizations bifurcate at a freezing temperature, T f  = 4.45 K, which yields the frustration parameter f = | θ CW | T f > 5 . AC susceptibility, shows a cusp-like peak at around T f , with the peak position shifting as a function of the driving frequency, confirming a spin-glass-like transition in LRMO. LRMO also shows typical spin-glass characteristics such as memory effect, aging effect and relaxation. In the heat capacity, there is no sharp anomaly down to 2 K indicative of long-range ordering. The field sweep 7Li NMR spectra show broadening with decreasing temperature without any spectral line shift. The 7Li NMR spin-lattice and spin-spin relaxation rates also show anomalies due to spin freezing near T f .