磁控溅射制备Mn-Co-Ni-O热敏红外探测薄膜

尖晶石Mn-Co-Ni-O三元氧化物具有优良的负温度系数（NTC），是一种制作热敏红外探测器较为理想的材料。采用射频磁控溅射法在非晶Al2O3衬底上制备了Mn1.56Co0.96Ni0.48O4（MCNO）多晶薄膜。使用能量色散X射线谱（EDS）对薄膜中金属元素组分进行了测量，分析得出薄膜中金属元素组分与靶材中的组分偏离在5%以内。对经过750℃空气中退火后的薄膜结构、电学和光学性质也进行了研究。实验结果表明:退火后薄膜具有单一立方尖晶石结构，且薄膜表面致密、均匀性好；薄膜的传导机制遵循小极子跃迁传导，在240~330K范围内符合VRH模型，其激活能和电阻温度系数（TCR）在室温下（300K）分别为0.297eV和-3.83%K-1；薄膜在紫外-可见波段具有较高的吸收率，间接带宽为0.61eV。

Preparation of Mn-Co-Ni-O films by RF magnetron sputtering for IR thermal detectors

Mn-Co-Ni-O spinel, owing to its low resistivity and large temperature dependent resistivity, is an attractive ternary system for thermistor applications and infrared detecting bolometers. Mn1.56Co0.96Ni0.48O4 (MCNO) polycrystalline films for infrared detection were successfully deposited on amorphous Al2O3 substrates by radio-frequency (RF) magnetron sputtering. Energy dispersive spectroscopy (EDS) indicates, for all the MCNO films, that the deviations of metallic element composition rank less than 5% comparing to the target. Structural, electrical, optical properties of MCNO films annealed at 750℃ were also investigated. X-ray diffraction shows the 750℃ annealed sample has a single cubic spinel phase, and the film is of favorable crystallization and compact density. The conduction mechanism of MCNO thin film follows the small-polaron hopping model, and the hopping type is variable-rangehopping (VRH) at 240-330 K. The TCR and the activation energy of MCNO films at room temperature (300 K) is 0.297 eV and-3.83%K-1, respectively. Also, the absorption coefficient has a relatively high value in the region of ultraviolet-visible and the indirect band gap is about 0.61 eV.