Fluctuating ferromagnetic phases

Fig. 16 (a) Phase diagram of K-(hg-ET)2Cu[N(CN)2]Cl determined from conductivity and magnetic measurements [213, 217, 218], N1-N4 nonmetallic phase, M metallic phase, RN reentrant nonmetallic phase, I-SC-I, II incomplete superconducting phase, S-SC complete superconducting phase. N2 shows the low-dimensional AF fluctuation. N3 shows growth of three-dimensional AF ordered phase. N4 weak ferromagnetic phase, (b) Proposed phase diagram [211, 212]... 

Further evidence for phase segregation above and below Tc has been obtained with a variety of other techniques in addition to Mossbauer [ 117,118] and EXAFS [119]. In Lao.7Cao.3Mn03, Quijada et al. [122] have been able to describe the structure of the low-energy optical conductivity with a two-phase model. Kim et al. [ 123] came to a similar conclusion from their optical-conductivity data, and Zhao et al. [124] used pulsed laser excitation to reveal a fast transient associated with photoionization of the polaronic phase and a slow transient associated with the ferromagnetic phase in Lao.7Cao3Mn03. Sakaie et al. [125] have confirmed with La NMR a slow correlation time for the spin-spin fluctuations of the ferromagnetic clusters and reported an... 

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