The effect of the preparation method and grain morphology on the physical properties of A2FeMoO6 (A=Sr,Ba)

Effect of the internal pressure and the anti-site disorder on the structure and magnetic properties of ALaFeTiO6 (A=Ca, Sr, Ba) double perovskite oxides

“…This means that the Fe 3 þ ions will reside in two different electronic environments. In the first environment, an octahedron of FeO 6 (T1 site) is surrounded by six TiO 6 octahedrons and in the second one the FeO 6 (T2 site) octahedron is surrounded by a combination of TiO 6 and FeO 6 octahedra. Thus, the charge density distribution in the T1 site would be different from that in the T2 site which would affects the isomer shift.…”

“…Shaheen et al [7] have studied ALaFeMnO 6 (A ¼Ca, Sr, Ba) by means of X-ray, neutron diffraction and Mössbauer spectroscopy. They found that the room-temperature measurements of the Mössbauer spectra are doublets with a quadruple splitting equals 0.43 mm/s for CaLaFeMnO 6 and increases to 0.6 mm/s in BaLaFeMnO 6 . Similarly, SrLaFeRuO 6 shows room temperature quadruple splitting equals 0.43 mm/s [8], and the origin of this quadruple splitting was related to the non-cubic crystal structure of the studied materials.…”

“…The disordered arrangement of the B and the B 0 is known as the anti-site effect, which leads to B-O-B, B 0 -O-B 0 and B-O-B 0 interactions that by their role affect the magnetic and electrical properties of the DP. Rubi et al [6] showed by means of magnetization and Mössbauer studies that the anti-site effect introduces near neighbour antiferromagnetic interactions between the Fe ions in Nd-doped Ca 2 FeMoO 6 which lead to enhancement of the Curie temperature.…”

“…The general chemical formula of double perovskite oxides can be expressed as A 2 BB 0 O 6 , where A is an alkaline earth element such as Sr, Ca, Ba etc., and B site is occupied by the first row of the 3d magnetic elements in the periodic table. The B 0 site is occupied by the 4d non-magnetic elements, with O atom located in between forming alternate BO 6 and B 0 O 6 octahedra and B-O-B 0 bonds [1,2]. The wide range of these compounds is due to the variety of the magnetic (B) and non-magnetic B 0 elements as well as the A-site cations that can form stable double perovskites structures.…”

Structural, magnetic and electrical transport properties of Co doping in LaKFeMoO6 double perovskite

“…The structure should be a cubic system based on the tolerance factors. The tolerance factor of Ba 2 FeMoO 6 double perovskite is 1.050 and its crystal structure belongs to a cubic system [11]. In order to illustrate the correction of the structure the Rietveld refinement was carried out in several space groups P4/mmm, P4/m, P4 2 /n, Pn3 and P2 1 /n and the space group P2 1 /n is the most reasonable in these space groups.…”