Mössbauer Studies on the Tellurium-Selenium Mixed Chains

Abstract

¹²⁵Te Mössbauer absorption measurements have been carried out for Te–Se mixed chains confined in the one-dimensional channels of mordenite crystals as well as for the mixed chains in trigonal crystalline and amorphous phases. ¹²⁹I Mössbauer emission spectra have been also taken for ¹²⁹Te labeled amorphous and trigonal Te–Se mixtures. The quadrupole splitting at the ¹²⁵Te atom is found to be appreciably larger for the isolated chains than for the trigonal mixtures, suggesting that the anisotropy of Te bonding is increased by reducing the interchain coupling between the adjacent chains. Both ¹²⁵Te and ¹²⁹I Mössbauer results indicate that the molecular character is much stronger in the amorphous phase than in the trigonal phase.