Effects of neodymium doping on the structural and magnetic properties of the double perovskite Sr2−yNdyFe1+xMo1−xO6 compound

Abstract

Curie temperature (TC) of the ferromagnetic compound Sr2FeMoO6 can be modified by increasing the itinerant electrons at the Fermi level. Nd doping increases the electron density but the charge neutrality should be taken into account. In this work, a series of double perovskites Sr[Formula: see text]Nd[Formula: see text]Fe[Formula: see text]Mo[Formula: see text]O6 ([Formula: see text]y[Formula: see text]=[Formula: see text]0.0, 0.25, 0.5, 0.75 and 1.0) for both cases, the off-stoichiometric ([Formula: see text]x[Formula: see text]=[Formula: see text]0) and the stoichiometric ([Formula: see text]x[Formula: see text][Formula: see text][Formula: see text]0 with x[Formula: see text]=[Formula: see text]y/2) one, were synthesized via solid state route and discussed in detail. A crystalline structure transition was confirmed by X-ray diffraction analysis, showing a change of the lattice parameters and the unit cell volume as a function of Nd doping. It was also found that the nominal valence in Fe is mainly Fe[Formula: see text] and in Mo is Mo[Formula: see text]. The TC increases continuously with Nd doping in the stoichiometric case. The increase of the TC follows a competition with the substitution of Sr[Formula: see text] ions by Nd[Formula: see text] ions and the charge neutrality considered in our system.