Abstract Diluted magnetic oxides attracted a great interest in the last years as materials for spintronics and magnetoelectric devices. We propose in the present paper such a magnetoelectric ceramic system for an application as miniaturized resonator antenna in GHz range. BaTi1-xFexO3-x/2 (0 ≤ x ≤ 0.02) polycrystalline ceramics have been produced by solid state reaction. X-ray diffraction analysis and Rietveld refinement have shown that Fe doping of BaTiO3 lattice produces a transition from tetragonal crystalline symmetry (for x ≤ 0.01) to a superposition of tetragonal and hexagonal phases for the compositions x = 0.015 and 0.02. As result of Fe addition, the Curie temperature of BaTi1-xFexO3-x/2 ceramics exhibit a shift from 127 °C towards lower values and reaches 85 °C for x = 0.02. A competition between weak ferromagnetic and antiferromagnetic character as a function of composition and temperature is determined both by the presence of transition metal ion and of the oxygen vacancies. Due to its electromagnetic properties, an optimized composition x = 0.01 was used for producing a miniaturized antenna which was found to show a frequency dependent S11 response similar to the simulated one.

中文翻译：

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磁电 Ba(Ti1-xFex)O3-x/2 陶瓷的制备和功能表征。小型化谐振器天线的应用

摘要 近年来，稀磁性氧化物作为自旋电子学和磁电器件的材料引起了人们的极大兴趣。我们在本文中提出了一种磁电陶瓷系统，用于 GHz 范围内的微型谐振器天线。BaTi1-xFexO3-x/2 (0 ≤ x ≤ 0.02) 多晶陶瓷已通过固态反应制备。X 射线衍射分析和 Rietveld 精修表明，BaTiO3 晶格的 Fe 掺杂产生了从四方晶体对称性（对于 x ≤ 0.01）到四方相和六方相叠加的转变，组成为 x = 0.015 和 0.02。由于 Fe 添加，BaTi1-xFexO3-x/2 陶瓷的居里温度从 127 °C 向较低值转变，并在 x = 0.02 时达到 85 °C。作为组成和温度函数的弱铁磁和反铁磁特性之间的竞争是由过渡金属离子和氧空位的存在决定的。由于其电磁特性，优化的成分 x = 0.01 用于生产小型化天线，发现该天线显示出与模拟天线类似的频率相关 S11 响应。