Cr、Co、Mn磁性对ZnO压敏特性影响的机理研究  

Effects of Magnetism for Cr,Co,Mn on the Current-Voltage Characteristics of ZnO Varistor

作　　者：王立惠[1] 甘国友[1] 孙加林[2] 严继康[1] 

机构地区：[1]昆明理工大学材料与冶金工程学院,昆明650093 [2]中国有色矿业集团有限公司,北京100055

出　　处：《半导体技术》2009年第6期576-578,618,共4页Semiconductor Technology

基　　金：云南省科技攻关项目(2002GG09);昆明理工大学科研基金项目(2007-15)

摘　　要：研究了不同浓度Cr、Co和Mn的掺杂对ZnO-PbO-B2O3陶瓷压敏特性的影响。实验表明,ZnO平均晶粒尺寸随各元素掺杂量增加而逐渐变大,压敏电压也随之升高,非线性系数随各元素掺杂量增加而先增大后减小,漏电流先减小后增大。分析认为,过渡族金属元素掺杂对ZnO压敏材料电性能的影响不仅与电子的能级有关,与其自旋特性也紧密相连。ZnO中掺杂的Cr、Mn、Co元素随机取代其中的部分Zn原子后,Cr2+、Mn2+、Co2+在ZnO中产生局域磁矩,会对与其取向不同的自旋电子产生强的散射,这样可增大ZnO陶瓷电阻率和提高其非线性特性。The effects of amount of Cr, Co and Mn doping on the current-voltage characteristics of ZnO-PbO- B2O3 varistor are summarized. It was found that the average grain size of ZnO and the breakdown voltage gradient increased with the increase of the concentration of Co2O3, MnO2 and Cr2O3, the nonlinearity coefficients will be greatly increased and then decreased, but leakage current density decreased and then increased. The current-voltage characteristics of ZnO decided by the electronic energy level structure, and associated with electronic spin of transition metal elements. Portion of Zn in ZnO crystal randomly substituted by Mn, Cr or Co elements, gave rise to localized magnetic moments and the highly scattering to electronics with different spin orientation, favorable for increasing the resistivity and nonlinear characteristics of ZnO varistor.

关 键 词：压敏材料 电性能 过渡元素 自旋相关输运 

分 类 号：TN304[电子电信—物理电子学]