Spin-glass-like state

In the paramagnetic regime (T > Tm), the spectra in a weak LF (needed to suppress the depolarization by Cu nuclear dipoles) for x > 0.08 were most easily fitted to a power exponential (exp[—(At) ]) relaxation. Hence the summary label relaxation rate in fig. 113 (left) refers to the static width Aeff (see eq. 74) for T dynamic rate A for r > Tu- The variation of power p was studied in some detail for the 10% sample. A decrease fromp w 1 at high temperatures top w 0.6 close to Tm was found. This is another indication that a disordered spin-glass-like state is approached and 7m might best be considered a spin freezing temperature. This spin-glass-like state, however,... 

Whether this spin-glass-like state will evolve into normal long-range ordered AFM for values of x exceeding 0.3 remains an open question. In fig. 115 (right) one observes that... 

Summary The formation of a spin-glass-like state is observed for a part of the sample. The cause for this inhomogeneous magnetism remains unknovm. The presence of spin glassy magnetism allows the interpretation of the low-temperature behavior of Sm3Se4 in terms of magnon-type excitations in contrast to the HF scenario. A final resolution has not been achieved. 

In many cases the relaxation of the magnetization is found to depend exponentially on the barrier but the pre-exponential factor tq was orders of magnitude shorter than observed in SMM. This behaviour is generally attributed to a transition to a spin glass-like state, SGL. 

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