巨介电常数材料 CCTO 的可变程跳跃电导研究
林 鹏1,2黄海涛3叶 茂1,2曾燮榕1,2柯善明1,21
【摘 要】文章研究了巨介电常数材料 CaCu3Ti4O12(CCTO)在宽温区(—120℃～300℃)及宽频域(1 Hz～10MHz)的交流电导及介电性能。在低温区和高温区，CCTO 表现出两种不同的导电过程，均可以由 Mott 提出的可变程跳跃电导机制(Variable-Range-Hopping，VRH)来描述。研究发现高温VRH 过程与氧空位的二次离子化相关，而低温过程符合普适介电响应方程，其介电弛豫行为起源于极化子的弛豫。 【期刊名称】集成技术 【年(卷),期】2014(000)006 【总页数】6
【关键词】CCTO；巨介电常数；可变程跳跃电导；极化子弛豫
1 Introduction
CaCu3Ti4O12(CCTO) has been reported to have a perovskite structure and a colossal dielectric constant (CDC) in the order of 105, which is almost independent of temperature from 400 K to 100 K but drops dramatically to less than 102 below 100 K[1]. Since then a huge amount of work[1-5]has been accomplished in an attempt to understand the origin of these remarkable dielectric properties. Similar dielectric behavior has been observed in chargedensity-wave (CDW) systems[6]. CDW materials are generally metals in low dimensions with a critical temperature, below which an insulating state could be observed. CCTO
巨介电常数材料CCTO的可变程跳跃电导研究
