Dielectric relaxation, resonance and scaling behaviors in Sr3Co2Fe24O41 hexaferrite.
Dielectric relaxation, resonance and scaling behaviors in Sr3Co2Fe24O41 hexaferrite.
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Sr3Co2Fe24O41六方铁氧体的介电弛豫、共振和结垢行为
DOI：
10.1038/srep13645
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发表时间：
2015-08-28
影响因子：
4.6
通讯作者：
Yang H
中科院分区：
文献类型：
--
作者：
Tang R;Jiang C;Qian W;Jian J;Zhang X;Wang H;Yang H
研究了Z型六角铁氧体Sr 3Co 2Fe 24 O 41（SCFO）在153 ~ 503 K、1 ~ 2 GHz范围内的介电性能。SCFO的介电响应被发现是频率依赖性和热激活。弛豫型介电行为被观察到是占主导地位的低频区域和共振型介电行为被发现是占主导地位的108 Hz以上。这种介电行为的频率依赖性解释的阻尼谐振子模型与温度相关的系数。阻抗谱的虚部（Z″）和模量谱的虚部（M″）表明弛豫时间存在一定的分布。Z″和M″谱的标度行为进一步表明弛豫时间的分布在低频下与温度无关。不同温度下的介电损耗谱在108 Hz以上没有显示出标度行为。通过对Z″和M″谱的比较表明，在低温下，短程电荷运动占主导地位，而在高温下，长程电荷运动占主导地位.上述结果表明，在SCFO的介电色散机制是温度无关的在低频和温度依赖于在高频下，由于共振行为的支配。
The dielectric properties of Z-type hexaferrite Sr3Co2Fe24O41 (SCFO) have been investigated as a function of temperature from 153 to 503 K between 1 and 2 GHz. The dielectric responses of SCFO are found to be frequency dependent and thermally activated. The relaxation-type dielectric behavior is observed to be dominating in the low frequency region and resonance-type dielectric behavior is found to be dominating above 108 Hz. This frequency dependence of dielectric behavior is explained by the damped harmonic oscillator model with temperature dependent coefficients. The imaginary part of impedance (Z″) and modulus (M″) spectra show that there is a distribution of relaxation times. The scaling behaviors of Z″ and M″ spectra further suggest that the distribution of relaxation times is temperature independent at low frequencies. The dielectric loss spectra at different temperatures have not shown a scaling behavior above 108 Hz. A comparison between the Z″ and the M″ spectra indicates that the short-range charges motion dominates at low temperatures and the long-range charges motion dominates at high temperatures. The above results indicate that the dielectric dispersion mechanism in SCFO is temperature independent at low frequencies and temperature dependent at high frequencies due to the domination of resonance behavior.