Successive phase transitions in the highly ordered complex perovskite PbLu1/2Nb1/2O3 |
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| Authors: | Yung Park Kevin M Knowles Kurn Cho |
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| Institution: | 1. Department of Materials Science and Metallurgy , University of Cambridge , Pembroke Street, Cambridge, CB23QZ, UK;2. Phone: 44-1223-334-342 Fax: 44-1223-334-342 E-mail: yp204@cam.ac.uk;3. Department of Materials Science and Metallurgy , University of Cambridge , Pembroke Street, Cambridge, CB23QZ, UK;4. Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology , Kusong-dong, Yusong-gu, Taejon, 371-1, Korea |
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| Abstract: | The structural phase transitions and the electrical behaviour of the complex perovskite PbLu1/2Nb1/2O3 have been investigated using X-ray powder diffraction, dielectric constant measurements, differential scanning calorimetry and measurement of the polarisation as a function of applied electric field. The high-temperature paraelectric phase is highly ordered. A first-order paraelectric-antiferroelectric phase transition occurs at 270°C and an antiferroelectric-ferroelectric phase transition, characterised by dispersion in the curves of dielectric constant as a function of temperature, occurs at ≈ 30°C. The antiferroelectric phase is isostructural with the orthorhombic form of PbYb1/2Nb1/2O3. The low-temperature ferroelectric phase also has an orthorhombic crystal structure. |
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| Keywords: | PbLu1/2Nb1/2O3 Phase transitions X-ray powder diffraction Antiferroelectricity Ferroelectricity |
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