Fast protector against EMP using electrical field induced resistance change in La/sub 0.67/Ca/sub 0.33/MnO/sub 3/ thin films

La/sub 0.67/Ca/sub 0.33/MnO/sub 3/ thin films were investigated using nanosecond duration electrical pulses. It was found that strong (up to 30 kV/cm) electric fields significantly reduces the resistance of the film and shifts the peak in resistance vs. temperature dependence to higher temperatures. The results are discussed using a model based on fast spin and charge system response to electric field action on the magnetic material. It was concluded that electric field induced changes in the La/sub 0.67/Ca/sub 0.33/MnO/sub 3/ thin film's resistance can be used to protect fast 50 ohm impedance high frequency transmission lines against short rise time fault current pulses.