Structural and phase relationships among trivalent tungstates and molybdates

Growth and characterization of ferroelectric‐ferroelastic Tb2(MoO4)3 crystals

“…The as-grown crystals showed no facets as the natural grown ones. After the orientation analysis to the crystals, we found that the crystals grown by natural direction are [110], which corresponds to the previous report [6].…”

“…The transmittance spectra of TMO crystal perpendicular to (001) plane in the air is shown in figure 4. From the plot it can be seen that the transmittance of TMO crystal is above 60% within the entire visible and most nearinfrared region except for the absorption around 485 nm, we presumed that it attributes to the absorption by Tb 3+ [6]. The good transmittance of TMO shows a promising prospect on nonlinear optical field in visible and near-infrared region.…”

“…While there are few detailed reports on the crystal growth of TMO, Kestigian et al first reported Czochralski (CZ) growth of several rare-earth molybdates of type M 2 (MoO 4 ) 3 , but failed in TMO for a destructive phase transformation during the cooling cycle [5]. Other descriptions on growth of β′-TMO crystals were only mentioned briefly [6,7]. In our laboratory, single crystal growth by the CZ method of β′-TMO has been tried and some preliminary results on study of crystal defects have been obtained [8].…”

Атомистическое Моделирование Сегнетоэлектрика-Сегнетоэластика Молибдата Гадолиния

“…Хотя ромбическая β ′ -модификация термодинамически метастабильна [6], однако кинетически она очень устойчива и в условиях окружающей среды может годами сохранять свое состо-яние, не переходя в низкотемпературную моноклинную α-фазу [7]. Кристаллическая структура β ′ -GMO изуча-лась в целом ряде работ [1][2][3][8][9][10][11][12][13].…”

Exciton and recombination luminescence of Al 2 (WO 4 ) 3 crystals

“…The good agreement between the threshold energy of e-h pair creation in a certain metal tungstate and the band-gap width in the corresponding metal oxide, observed for several tungstate crystals [1], seems to support the latter suggestion. To prove the important role of cationic states in the formation of free electrons and holes in oxyanionic crystals, we have chosen to study and synthesize a tungstate material Al 2 (WO 4 ) 3 with a cation, whose oxide has one of the largest band-gaps known among oxide crystals (9.4 eV for α-Al 2 O 3 [2]).Aluminium tungstate has an orthorhombic structure and belongs to the Pnca space group [3]. This little-known compound attracted attention of researchers as a trivalent cation ionic conductor [4][5][6] and when doped with trivalent ions, e.g.…”