Evidence for an exotic magnetic transition in the triangular spin system FeGa2S4

Abstract

We report positive muon spin relaxation measurements on the triangular lattice magnetic system FeGa2S4. A magnetic transition not previously detected by specific heat and magnetic susceptibility measurements is found in zero field at T * ≃ 30 K. It is observed through the temperature dependencies of the signal amplitude and the spin-lattice relaxation rate. This transition is therefore not a conventional magnetic phase transition. Since persistent spin dynamics is observed down to 0.1 K, the ground state cannot be of the canonical spin-glass type, which could be suggested from hysteresis effects in the bulk susceptibility below T f ≃ 16 K. These results are compared to those found for the isomorph NiGa2S4. It is argued that the fate of the transition, which has been interpreted in terms of the Z2 topological transition in this latter system, is probably different in FeGa2S4.

Magnetic Order, Spin Waves and Fluctuations in the Triangular Antiferromagnet La2Ca2MnO7

“…(3). The same thermal behavior has been reported for Li 2 RuO 7 via 7 Li nuclear magnetic resonance, 51 and for FeGa 2 S 4 , 15,48 NiGa 2 S 4 , 15 and -KCrO 2 52 by SR measurements. However, J extracted from the¯t, i.e., J Z , is only approximately 70% of the value derived from the speci¯c heat which is probably the most reliable estimate obtained of J in this study; see Sec.…”

“…The sibling compound FeGa 2 S 4 also displays a spin-disordered ground state. 15 The range of the exchange interaction has not be determined experimentally.…”

Magnetic phase diagram ofBa3CoSb2O9as determined by ultrasound velocity measurements

“…Such persistent spin dynamics (PSDs) are a common feature of frustrated magnets as seen by muon spin rotation (µSR), neutron spin echo and Mössbauer spectroscopy measurements. [29][30][31][32] To our knowledge, this is the first observation of such residual fluctuations with sound velocity measurements. Zhou et al…”

Ground-state properties of the triangular-lattice Heisenberg antiferromagnet with arbitrary spin quantum number s

“…Refs. [44][45][46][91][92][93][94]. As already mentioned above, the compounds Ba 3 CoSb 2 O 9 and Ba 3 NiSb 2 O 9 are described well by the Heisenberg model considered here with spin quantum number s = 1/2 (Ba 3 CoSb 2 O 9 ) [45] and s = 1 (Ba 3 NiSb 2 O 9 ) [44,48].…”