Search for a second frequency signal in magnetite (Fe₃O₄) in the T_V –T_W range: a Maximum-Entropy μSR study

The local magnetism in Fe₃O₄ has been previously studied through muon-spin rotation (μSR) showing a single frequency signal. [1] Results indicate a transitionat T_V (123 K) for the Verwey transition and a transition at T_W (247 K) about twice T_V . The transition at T_W is not well understood, but suspected to be a precursor of the Verwey transition. [1] μSR time series of single crystals of magnetite indicate at a beat pattern, suggesting a second signal. By means of Maximum Entropy, we analyze transverse and zero field μSR single Xtal Fe₃O₄ data to search for a second signal in the T range above T_V and below T_W. [2]. The existence of this second signal of Fe₃O₄ in the T_V -T_W region could be related a phonon-assisted 3d-electron hopping in Fe₃O₄. [3] Thus, a second frequency signal or lack thereof in low fields may lead to a better understanding of the local magnetism, conduction mechanism, the Verwey transition and its precursors in the Fe₃O₄ Mott-Wigner glass.
[1] C Boekema et al, Hpf Interactions 31 (1986) 487; Phys Rev B31 (1985) 1233. [2] C Boekema and MC Browne, MaxEnt 2008, AIP Conf Proc #1073 p260.[3] C Boekema et al, Proc 11th Int M2S Conf (2015).