用脉冲激光方法在Si(100)上沉积的Cox-C1-x颗粒膜及其磁电阻效 应

利用脉冲激光沉积方法在Si(100)上制备了Co_x-C_1-x颗粒膜，并研 究了其正磁电阻 效应.实验结果表明，样品在室温下的正磁电阻效应要远远高于低温下的正磁电阻效应；Co _0.02-C_0.98样品具有最大的室温正磁电阻效应，在外加磁场B=1T时 ，其磁电阻 率MR=22%；随着Co含量的增加，Co_x-C_1-x颗粒膜的正磁电阻效应呈 减小趋势.样品 的MR-B的曲线与传统的多 关键词： 正磁电阻效应 x-C_1-x颗粒膜')" href="#">Co_x-C_1-x颗粒膜 脉冲激光沉积

Large magnetoresistance in Cox-C1-x granular films on Si(1 00) substrate prepared by pulsed laser deposition

A large positive magnetoresistance (MR) has been observed in Co_x-C1-x gr anular films prepared on Si(100) substrates by pulsed laser deposition (PLD). Co _0.02-C_0.98 sample has the largest room-temperature MR of 2 2% at the magnetic field B=1T. It is noted that in the Co_x-C_1-x/Si s tructure, the MR at room-temperature is much larger than that at low temperatures. The room-te mperature positive MR of the Co_x-C_1-x films has a B^{2/ 3} dependence when B＜1T and a B^1/2 dependence when B＞1T. Such magnetotransport pr opert ies have never been reported before. It appears that some new mechanisms play im portant roles in the magnetotransport of the Co_x-C_1-x film s. Further stu dy on the MR mechanism of the Co_x-C_1-x/Si structure will n ot only shed l ight on the study of spin electronics and magnetism, but also make possible the application of the Co_x-C_1-x/Si in information industry.