Improvement of electrical properties of single-phase film thermistors by a Ni<sub class="a-plus-plus">0.75sub>Mn<sub class="a-plus-plus">2.25sub>O<sub class="a-plus-plus">4sub>/LaMnO<sub class="a-plus-plus">3sub> bilayer structure
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- 作者：Wenwen Kong ; Qin Shi ; Bo Gao ; Aimin Chang
- 刊名：Journal of Materials Science: Materials in Electronics
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：28
- 期：4
- 页码：3837-3842
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Optical and Electronic Materials; Characterization and Evaluation of Materials;
- 出版者：Springer US
- ISSN：1573-482X
- 卷排序：28
文摘
The LaMnO<sub>3sub> film, Ni<sub>0.75sub>Mn<sub>2.25sub>O<sub>4sub>/LaMnO<sub>3sub> supported bilayers and Ni<sub>0.75sub>Mn<sub>2.25sub>O<sub>4sub> film thermistors have been successfully fabricated through pulsed laser deposition (PLD) method. XRD analysis reveals that no chemical reaction occurs between LaMnO<sub>3sub> and Ni<sub>0.75sub>Mn<sub>2.25sub>O<sub>4sub> during deposition in the coexistence of bilayer materials. However, the resistivity at room-temperature of thin film with a Ni<sub>0.75sub>Mn<sub>2.25sub>O<sub>4sub>/LaMnO<sub>3sub> bilayer is 19.6 Ω cm. It is much lower than the resistivity of the LaMnO<sub>3sub> (580 Ω cm) and Ni<sub>0.75sub>Mn<sub>2.25sub>O<sub>4sub> single phase films (94.2 Ω cm). Such feature is attributed to the existence of the parallel equivalent circuit in bilayer, the decrease in the grain boundary area and the increase in Mn3+/Mn4+ ratio. In addition, the electrical measurement shows that the thermal constant of the bilayer samples are almost the same as that of single layer Ni<sub>0.75sub>Mn<sub>2.25sub>O<sub>4sub> film. This study suggests that a bilayer concept is proposed to adjust the electrical properties of NTC thermistors. We believe the above results are very instructive for the applications and further research of Mn-based NTC oxides.