High-temperature properties of the Sr2FeMoO6 double perovskite: Electrical resistivity, magnetic susceptibility, and ESR

D. NIEBIESKIKWIAT; R.D. SANCHEZ; A. CANEIRO; L. MORALES; M. VASQUEZ MANSILLA; F. RIVADULA; L.E. HUESO

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2000 vol. 62 p. 3340 - 3345

1098-0121

In this work we present electrical resistivity, magnetic susceptibility, and electron spin resonance data athigh temperature of the Sr2FeMoO6 double perovskite. We found between 300 K and 900 K two metalinsulatortransition temperatures at Tc'405 K and '590 K respectively. Below the first transition, the materialis metallic and magnetically ordered. Above 590 K, r shows a metallic behavior again, while in the range405 K<T<590 K we observed a weak localization. The magnetic susceptibility can be described taking intoaccount localized and itinerant electrons. The paramagnetic resonance of Fe31 ions with g52.009(5) can bestudied in temperature. Above Tc the linewidth data present similar behavior to that of manganese perovskites,with a relaxation mechanism related to spin-spin interactions. The intensity of the resonance line decreaseswith T faster than a Curie law expected, due to a reduction in the number of localized spins of the Fe31 ions.At high temperatures (T>520 K! we observe a second paramagnetic resonance line with g51.995(1) associatedwith a small amount of Mo51 ions.