PT has a perovskite structure of the tetragonal
type, space group P4/mmm (crystallographic report 06-0452), while ST has a cubic structure with a Pm-3m space group (crystallographic report 035-0734).
These shapes are reported as egg-shape, oval, round, irregular, tetragonal
, pentagonal, hexagonal and heptagonal.
4 that the catalyst calcined at 550 AoC has a tetragonal
phase and higher acidity.
Particularly, precisely controlled and optimized stoichiometry in Al-ZrHf[O.sub.2] ternary composition caused a tetragonal
phase generating a high dielectric constant.
Somiya, "Calibration curve for quantitative analysis of the monoclinic tetragonal
ZrO2 system by X-rays diffraction," Journal of the American Ceramic Society, vol.
XRD data shows that the synthesized powders were comprised of tetragonal
CIS materials (JCPDS card number 040-1487).
In Table 1, we list the lattice structures of LiFeAs and NaFeAs with the tetragonal
structure under different pressures.
The formation of some quaternary with compositions Cu-II-III-[Se.sub.3] (x = 1/2), Cu-[II.sub.2]-III-[Se.sub.4] (x =2/3) and [Cu.sub.2]-II-III-[Se.sub.5] (x = 1/3) have been reported [8-11], and the first crystal structure characterization of one I-II-III-[VI.sub.3] semiconductor member, indicated a degradation of symmetry from the chalcopyrite structure 14 2d to a related tetragonal
structure P 4 2c .
The anomaly of the bulk coefficient of thermal expansion at the transition from the cubic to the tetragonal
phase was found to remain distinct enough while its intensity is decreasing with the decrease of x.
syngony (classes 4, [bar.4], 4/m) Duhamel-Neumann expression (4) can be written in matrix form as