Żukowski Paweł, Gałaszkiewicz Piotr, Bondariev Vitali, Okal Paweł, Pogrebnjak Alexander, Kupchishin Anatolyi, Ruban Anatolyi, Pogorielov Maksym, Kołtunowicz Tomasz N
Department of Electrical Devices and High Voltage Technology, Lublin University of Technology, 38A, Nadbystrzycka Str., 20-618 Lublin, Poland.
Department of Nanoelectronics and Surface Modification, Sumy State University, 2, R-Korsakov Str., 40007 Sumy, Ukraine.
Materials (Basel). 2022 Nov 9;15(22):7908. doi: 10.3390/ma15227908.
In this paper, the frequency-temperature dependence of the conductivity and dielectric permittivity of nc-TiZrC+α-C (0.0 ≤ ≤ 1.0) nanocomposites produced by dual-source magnetron sputtering was determined. The films produced are biphasic layers with an excess of amorphous carbon relative to the stoichiometric composition of TiZrC. The matrix was amorphous carbon, and the dispersed phase was carbide nanoparticles. AC measurements were performed in the frequency range of 50 Hz-5 MHz at temperatures from 20 K to 373 K. It was found that both conductivity and permittivity relationships are determined by three tunneling mechanisms, differing in relaxation times. The maxima in the low- and high-frequency regions decrease with increasing temperature. The maximum in the mid-frequency region increases with increasing temperature. The low-frequency maximum is due to electron tunneling between the carbon films on the surface of the carbide nanoshells. The mid-frequency maximum is due to electron transitions between the nano size grains. The high-frequency maximum is associated with tunneling between the nano-grains and the carbon shells. It has been established that dipole relaxation occurs in the nanocomposites according to the Cole-Cole mechanism. The increase in static dielectric permittivity with increasing measurement temperature is indicative of a step polarisation mechanism. In the frequency region above 1 MHz, anomalous dispersion-an increase in permittivity with increasing frequency-was observed for all nanocomposite contents.
本文测定了通过双源磁控溅射制备的nc-TiZrC+α-C（0.0≤≤1.0）纳米复合材料的电导率和介电常数随频率和温度的变化关系。所制备的薄膜是两相层，相对于TiZrC的化学计量组成，其非晶碳过量。基体为非晶碳，分散相为碳化物纳米颗粒。在50Hz至5MHz的频率范围内、20K至373K的温度下进行了交流测量。结果发现，电导率和介电常数关系均由三种隧穿机制决定，它们的弛豫时间不同。低频和高频区域的最大值随温度升高而降低。中频区域的最大值随温度升高而增加。低频最大值是由于碳化物纳米壳表面碳膜之间的电子隧穿。中频最大值是由于纳米尺寸晶粒之间的电子跃迁。高频最大值与纳米晶粒和碳壳之间的隧穿有关。已经确定，纳米复合材料中偶极子弛豫按照科尔-科尔机制发生。静态介电常数随测量温度升高而增加，这表明存在阶跃极化机制。在1MHz以上的频率区域，对于所有纳米复合材料含量，均观察到反常色散——介电常数随频率增加而增加。
