TEMPERATURE-DEPENDENT RAMAN STUDIES OF BA(MG1 3TA2/3)O-3/

Microprobe Raman spectroscopy has been used to study ceramics and sing le-crystal fibres of BaMg1/3Ta2/3O3. According to x-ray diffraction, c eramics exhibit 1:2 order on the B sites whereas fibres remain disorde red. The Raman spectra, however, are almost identical in both cases an d are mostly consistent with 1:1 short-range order in nanoscale region s. Some extra lines of weak intensity originate from distortions in mi crostructures, probably providing charge compensation. Raman scatterin g measurements did not reveal the existence of 1:2 ordering in the nan oscale region in ceramics or single crystals.