Temperature induced structural phase transition in Sr3-Ca Fe2TeO9 (0 ≤ x ≤ 1) probed by Raman and Mossbauer techniques

Crystallography at non-ambient conditions and physical properties of the synthesized double perovskites, Sr2(Co1−xFex)TeO6

“…Close to the side of 2θ = 46°, a shoulder of this reflection appears at approximately 540(5) K, which does not describe either the monoclinic or the cubic symmetries. This shoulder is a feature of an intermediate tetragonal phase with the space group I4/m, although the presence of such a shoulder can clearly be seen in the XRD data reproduced by A. Faik et al 73 From Fig. 3(b), the second phase transition from I2/m to I4/m is clearly observed.…”

“…The diminution of the atomic distance gives rise to strong interactions between Fe and the six atoms of oxygen, which increase the electric field gradient and then increase the quadrupole splitting (QS) as well. 71,73 As a result, the octahedral site (2d ) could be more deformed than the octahedral site (2a).…”

Studies of dielectric and piezoelectric properties of PbTi0.8−x Te0.2GdxO3 nano ceramics prepared by high energy ball milling

“…[1][2][3][4] Variation of properties of ferroelectric materials are dependent on method of fabrication, at the same time, incorporation of foreign element in lattice site of material changes the property radically. There are different methods of fabrication reported by workers [5][6][7][8][9][10][11][12][13][14][15][16] such as sol-gel. Co-precipitation, etc.…”

Synthesis and Rietveld refinements of new ceramics Sr2CaFe2WO9 and Sr2PbFe2TeO9 perovskites

“…The antisitedisorder was also observed in several triple perovskites, such as Sr 3 Fe 2 TeO 9 (S space group I4/m), Ba 3 Fe 2 TeO 9 (space group P6 3 /mmc) (Ivanov et al, 2007;Tang et al, 2016), Ca 3 Fe 2 WO 9 (space group I4/m) (Ivanov et al, 2005), Sr 3 Fe 2 MoO 9 (space group I4/m), Sr 3 Fe 2 WO 9 (space group I4/m), Sr 3 Fe 2 UO 9 (space group I4/m) (Viola et al, 2003), Ba 1.6 Sr 1.4 Fe 2 WO 9 (space group P6 3 /mmc) (Manoun et al, 2011). Recently perovskite series Sr 3−x Ca x Fe 2 TeO 9 (0 ⩽ x ⩽ 1) (El Hachmi et al, 2017) were reported by our research team showing that the antisite-disorder is affected with increasing the Calcium amount from x = 0 to x = 1.…”