Fe-57 Mossbauer Spectroscopic Study For Fe(Pyridine) Ni-2(Cn)(4) Spin-Crossover Compound

We have measured the Fe-57 Mossbauer spectra of the Hofmann pyridine complex Fe(pyridine)(2)Ni(CN)(4) sample before and after exposure to high pressure of gaseous xenon. The temperature dependence of the high spin molar fraction has been determined from the Fe-57 Mossbauer spectra. The spin transition of the sample without the high pressure treatment occurs between 175 and 220 K with a hysteresis width of 15 K. Although the Fe-57 Mossbauer spectra suggest that the spin crossover behavior of the sample before and after the high pressure treatment are almost the same, the hysteresis of the latter sample is somewhat larger.