| La2/3TiO2.84 세라믹스의 전기전도특성 |
| 정우환 |
| 호원대학교 조명 인테리어학과 |
| Electrical Transport Properties of La2/3TiO2.84 Ceramic |
| Woo-Hwan Jung |
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| ABSTRACT |
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The thermoelectric power, dc conductivity and magnetic properties of the cubic L $a_{2}$ 3/Ti $O_{2.84}$ were investigated. The thermoelectric power was negative below 350 K. The measured thermoelectric power of L $a_{2}$ 3/Ti $O_{2.84}$ increased linearly with temperature, in agreement with model proposed by Emin and Wood, and was represented by A+BT. Temperature dependence indicates that the charge carrier in this material is a small polaron. L $a_{2}$ 3/Ti $O_{2.84}$ exhibited a cross over from variable range hopping to small polaron hopping conduction at a characteristic temperature well below room temperature. The low temperature do conduction mechanism in L $a_{2}$ 3/Ti $O_{2.84}$ was analyzed using Mott's approach. Mott parameter analysis gave values for the density of state at Fermi level [N( $E_{F}$)] = 3.18${times}$10$^{20}$ c $m^{-3}$ e $V^{-1}$ . The disorder energy ( $W_{d}$) was found to be 0.93 eV, However, it was noted that the value of the disorder energy was much higher than the high temperature activation energy. The exist linear relation between log($sigma$T)와 1/T in the range of 200 to 300 K, the activation energy for small polaron hopping was 0.15 eVeVeV5 eVeVeV |
| Key words:
dc conductivity, Mott′s parameter, Small polaron, variable-range hopping |
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