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Evidence for the existence of two electronic states in the chalcopyrite-type alloys CuFe(S<inf>1-z</inf>Se<inf>z</inf>)<inf>2</inf>

Abstract:

Results of Mössbauer spectroscopy for the chalcopyrite-type of alloys CuFe(S1-zSez)2 in the range of composition 0≤z≤0.45 are presented. Room temperature spectra show two contributions: one is a magnetic spectrum (six lines) with a value of the hyperfine field near to that of chalcopyrite (z=0, in which an antiferromagnetic order occurs below T=823 K), the other having only one line. The relative area of the single-line contribution increases as z increases. For z=0.2, we also made Mössbauer measurements as a function of temperature. The ratio of the two contributions evolves according to a Boltzmann law, in which the single line corresponds to the excited state at 81 K above the antiferromagnetic ground state. © 1994 J.C. Baltzer AG, Science Publishers.