Fabrication and enhanced electrical stability of Mn–Co–Fe–Zn–O NTC thin films by low temperature ion-beam-assisted deposition technology

Abstract

The Mn–Co–Fe–Zn–O negative temperature coefficient (NTC) thin films, vital for next-gen temperature sensors, face a pivotal hurdle in enhancing electrical stability. This study triumphantly crafted these films with ultra-high stability using ion-beam-assisted deposition (IBAD) at a relatively low temperature (240 °C). All films obtained under three different ion-beam types, Ar, O₂, and None, exhibit a dense, grain homogeneous morphology as well as a single spinel phase structure, and all show excellent NTC characteristics over the temperature range of 10–90 °C. The XRD peak shift and Raman signal attenuation indicate that ion-beam bombardment exerts control over the crystal structure. The application of Ar ion-beam assistance resulted in a significant reduction in film ageing drift, from 4.23% to 0.58%. This reduction was achieved by the Jahn–Teller distortions induced by the high concentration of Mn³⁺, and the low oxygen vacancy concentration. Further, the low processing temperature augments process compatibility with heat-sensitive substrates, safeguarding them from harm and hinting at vast potential in integrated circuits and innovative electronics manufacturing.