Meeting room "Glova", 4 floor, Integrated Research Building
Abstract
The transformation of the hexagonal wurtzite-type structure (B4) to the cubic rocksalt-type structure (B1) is a significant transition pathway in ANB8-N binary semiconductors. The general B4-B1 pathway, which itself cannot be observed directly, is still controversy and has stimulated many studies for the last few decades. In our recent work, the stoichiometric mixed-metal oxide LiGaO2, has been used as the ternary wurtzite-type model to elucidate the mechanistic details of the B4-B1 pressure-induced transitions in pure and deficient wurtzite-type semiconductors. Different from the binary wurtzites, there exist two different cation relaxations in the ternary wurtzite LiGaO2, the layer-rocksalt-type (R-3m) and newly-discovered disordered-rocksalt-type (Fm-3m) phases are the different products of the B4-B1 transition from ternary wurtzite-type (Pna21), and another newly-discovered metastable tetragonal I4/m structure LiGaO2 with c/a = 1.46 (slightly larger than ) is found to be the intermediate phase between the ternary wurtzite-type (Pna21) and the rocksalt-type phases (R-3m and Fm-3m). The B4- to B1-type path in binary wurtzite is generally not observed, but in the case of ternary wurtzite LiGaO2, the direct experimental observation of the tetragonal-type primitive cell structure with c/a = 1.46 after static compression of the wurtzite-type structure is undoubtedly strong evidence for the "tetragonal-type" transformation pathway scheme.
For inquiry：Taku Tsuchiya TEL:（089）927-8198
E-mail takut@sci.ehime-u.ac.jp
