Facile synthesis and physical properties of single-phase Sr2CrWO6 ceramics

Abstract

Preparation of single-phase Sr2CrWO6 ceramics is difficult since inevitable SrWO4 and Sr2WO5 parasitic phases are hard to remove. In this paper, pure Sr2CrWO6 (S1) ceramics were easily synthesized by changing the mixing procedure of raw materials of the solid-state reaction method. Furthermore, Sr2CrWO6 (S2) ceramics with parasitic phase SrWO4 were also prepared for comparison. The crystal structure, chemical states, and magnetic and transport properties of S1 and S2 were investigated. Although there were no distinct differences in the crystal structure and chemical states of S1 and S2, S1 exhibited a higher magnetization and Curie temperature than S2, and this is because of the suppressed magnetic interaction in S2 caused by the large amount of Cr/W anti-site defect content. Smaller grain size and looser grain connectivity resulted in a higher resistivity of S1 than that of S2. Moreover，S2 responded more sensitively to a magnetic field of 2 T at low temperature (T≤50K). It is interesting to note that an appreciable low-field magnetoresistance (LFMR; H = 0.5 T) was observed, reaching − 46.5% and − 34.6% at 3 K and − 20.1% and − 21.8% at 50 K for S1 and S2, respectively. This remarkable LFMR property indicates that Sr2CrWO6 ceramics may be a good candidate for practical applications in magnetic storage devices. It is possible that our work may not only provide an efficient experimental process for preparing other single-phase double perovskites that are difficult to synthesize but also provokes further investigation into the fundamental physical properties of magnetic double perovskites.