Dielectric anomalies in orthorhombic YMnO₃ thin films

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• 作者：I. Fina ; X. Martí ; L. Fà ; brega ; F. Sà ; nchez ; J. Fontcuberta
• 关键词：Dielectric ; Orthorhombic yttrium manganite ; Magnetoelectric ; Multiferroic
• 刊名：Thin Solid Films
• 出版年：2010
• 出版时间：1 June 2010
• 年：2010
• 卷：518
• 期：16
• 页码：4710-4713
• 全文大小：577 K

文摘

We report on the magnetodielectric characterization of orthorhombic (001) oriented YMnO₃ thin films grown by PLD on Nb-doped SrTiO₃. Detailed temperature, magnetic field and frequency dependent measurements are used to determine dielectric and magnetodielectric response and to analyse its origin. A dielectric peak below the Néel temperature is observed. We show that this peak signals a magnetoelectric coupling as inferred from a magnetocapacitance of about 2 % at 8 T and 25 K. A careful analysis of the impedance spectroscopy allows concluding that both the dielectric peak and the measured magnetocapacitance are intrinsic properties of YMnO₃. At higher temperatures (> 200 K) another dielectric feature (a strong frequency dependency and a peak in the dielectric losses) is observed, which is ascribed to the Maxwell–Wagner behaviour and thus it is not a genuine response of stoichiometric YMnO₃.