双钙钛矿Sr_2CrWO_6的磁性与输运性质研究

MAGNETIC AND TRANSPORT PROPERTIES IN THE DOUBLE PEROVSKITE Sr_2CrWO_6

研究了双钙钛矿Sr2 CrWO6的磁性和输运性质 .Sr2 CrWO6多晶在Ar气及真空气氛中经固相烧结而形成 .X射线衍射分析表明主相为Sr2 CrWO6,少量杂相为SrWO4 .热磁测量表明样品的居里温度为 480K左右 .电阻随温度降低而升高 ,类似于绝缘体 ,在外场 5T ,低温下 (2 5K)磁致电阻 (MR)可达 2 0 % ,但MR随温度升高而趋于零 .较大的矫顽力 (5 97× 10 4 A/m)以及低场部分MR

We have carried out preliminary investigations about the magnetic and transport properties of the double perovskite Sr2CrWO6. The polycrystalline sample was fabricated using solid-state reactions in an Ar atmosphere and evacuated silica capsules. The X-ray diffraction studies show that the sample is composed of Sr2CrWO6 and a small amount of impurity Sr-WO4. The Curie temperature, determined by the thermal magnetization measurements, is around 480 K. The electric resistivity increases with the drop of temperature and exhibits insulator behavior. A large intergrain magnetoresistance (MR) up to 20 % at; a low temperature (25 K) and a field of 5 T is observed. And the MR decreases to zero with increasing temperature toward 300 K. The large coercive force (5.97 x 10(4) A/m) and the low-field deviation of MR from high-field linear behavior indicate that there probably exists a large magnetic anisotropy in the compound.