摘要
采用紫外脉冲激光沉积技术分别在LaA lO 3(LAO)、(LaA lO 3)0.3-(SrA lT aO 6)0.7(LSAT)和SrT iO 3(STO)(001)单晶衬底上制备了La0.825Ca0.175MnO 3(LCMO)薄膜。实验发现衬底的晶格失配度和退火氧压对薄膜结晶质量和电学性能有重要影响。电阻-温度曲线显示,生长在LAO(压应变)的LCMO薄膜比生长在STO(拉伸应变)的薄膜有更高的绝缘体-金属转变温度Tp和更大的电阻温度系数(TCR)。增加退火氧压可以有效地提高薄膜的Tp和TCR值。当退火氧压为30000 Pa时,与衬底晶格失配度最小的LCMO/LSAT薄膜具有最高的Tp(234.5 K)和最大的TCR(22.4%)。实验结果表明Ca含量为0.175的La1-xCaxMnO 3薄膜材料在测辐射热计等方面有潜在的应用前景。
La0. 825Ca0. 175 Mn O3（ LCMO） thin films have been deposited on La AlO 3（ LAO）,（ La AlO 3）0. 3-（ SrA lT a O6）0. 7（ LSAT） and SrT iO 3（ STO）（ 001） oriented substrates,respectively,by pulsed laser deposition. The crystalline quality and electrical properties of films are found to be strongly influenced by the lattice-substrate mismatch and oxygen pressure in the annealing process. The resistances versus temperature curves show that the LCMO film grown on LAO（ compressive strain） has the higher insulator-metal transition temperature Tpand larger temperature coefficient of resistance（ TCR） than the film grown on STO（ tensile strain）. Increasing oxygen annealing pressure can effectively improve Tpand TCR values of the film. LCMO / LSAT with the smallest lattice-substrate mismatch exhibits the largest TCR value of 22. 4% with a higher Tp（ 234. 5 K） when annealing at 30000 Pa oxygen. But when annealed at 20000 Pa oxygen pressure the TCR is only 18. 1% near the Tpof 157. 1 K. The results show that La1- xCaxMn O3 thin film with the Ca content of 0. 175 is a very promising candidate for the application of bolometer.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2014年第11期2874-2879,共6页
Journal of Synthetic Crystals
基金
General Project of Science and Technology Department of Yunnan Province(KKSA201151081)
