Enhanced TCR with Room Temperature TMI for Potential Application in Microbolometer

Abstract

Polycrystalline samples Nd0.5La0.2Sr0.3MnO3 (NL) and Nd0.5La0.2Sr0.3MnO3 + 0.2Ag (NL + Ag) are prepared by solid state reaction technique. These compounds are found to be crystallized in orthorhombic structural form. On addition of silver (Ag), the temperature coefficient of resistance (TCR) is significantly improved near the metal–semiconductor/insulator transition (TMI) temperature. The TMI is increased from 288 K (for NL) to 302 K (for NL + Ag). Enhancement in TCR is explained on the basis of the grain growth and their connectivity. The reduction in grain boundaries between grains improved the conduction process. High TCR (5.1%) and room temperature TMI of NL + Ag sample are useful characteristics for MEMS-based uncooled microbolometer for infrared detection.