All samples are synthesized through a standard solid state reaction route and are quenched
to room temperature systematically at 700° C, 500° C, 300° C, and room temperature (RT);
the samples are denoted 700Q, 500Q, 300Q, and RTQ, respectively. The structural, and
magnetic properties are studied. Careful Rietveld analysis of the X-ray diffraction patterns
revealed that all samples except 700Q crystallized in a single phase with space group
P4/nmm; the amount of interstitial Fe (Feint) at the 2c site increased from 5% for RTQ to 8 …