Modelling the electric field effect in superconducting films

The sharp metal-to-insulator transition observed in several colossal magnetoresistive manganite (CMR) materials has led to interest in the use of CMR thin-films as bolometric detectors of infrared radiation. We have confirmed that with optimum growth and processing conditions, both high TCR (up to 30%/K) and low excess noise properties can be achieved in pulsed-laser deposited La0.7Ca0.3MnO3 thin films. These offer unprecendented levels of performance if used as resistance bolometers, however a degree of cooling from room temperature will be required to achieve maximum bolometer performance. We have shown that LaxBa1-xMnO3 is a candidate for uncooled bolometer operation and demonstrated room-temperature TCR values of 5%/K in both laser-deposited and liquid-delivery CVD deposited LBMO films. Further enhancement to these figures is expected with optimised processing.