Microwave Loss in the High-Performance Dielectric Ba(Zn1/3Ta2/3)O3 at 4.2 K
Microwave Loss in the High-Performance Dielectric Ba(Zn1/3Ta2/3)O3 at 4.2 K
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DOI：
10.1103/physrevlett.109.257601
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发表时间：
2012-12-18
影响因子：
8.6
通讯作者：
Newman, Nathan
中科院分区：
文献类型：
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作者：
Liu, Lingtao;Flores, Marco;Newman, Nathan
温度和磁场相关的测量的损耗角正切在Ba（Zn 1/3 Ta 2/3）O-3掺杂过渡金属（Mn，Ni）进行了比较，从掺杂其他杂质（Cd，Ga，Mg和Zr）的样品。这些结果，结合脉冲电子顺磁共振测量，最终表明，在低温下的过渡金属掺杂的Ba（Zn 1/3 Ta 2/3）O-3的微波损耗是由于未成对的过渡金属d电子在孤立的原子（轻掺杂）或交换耦合集群（中度到高度掺杂），一种机制，不同于通常的嫌疑人的共振自旋激发。
Temperature- and magnetic-field-dependent measurements of the loss tangent in Ba(Zn1/3Ta2/3)O-3 doped with transition metals (Mn, Ni) are compared to those from samples doped with other impurities (Cd, Ga, Mg, and Zr). These results, combined with pulsed electron paramagnetic resonance measurements, show conclusively that microwave loss in transition-metal-doped Ba(Zn1/3Ta2/3)O-3 at cryogenic temperatures is attributable to resonant spin excitations of unpaired transition-metal d electrons in isolated atoms (light doping) or exchange coupled clusters (moderate to high doping), a mechanism that differs from the usual suspects.