GROWTH OF IRON, NICKEL, AND PERMALLOY THIN-FILMS BY MOCVD FOR USE IN MAGNETORESISTIVE SENSORS

Thin films of elemental iron and nickel, plus a wide composition range of iron-nickel alloys, have been deposited by atmospheric pressure me tal organic chemical vapor deposition at a growth temperature of 200 d egrees C, using iron pentacarbonyl and nickel tetracarbonyl as the sou rce precursors. Detailed magnetoresistance measurements of the permall oy layers showed that the maximum value of magnetoresistance occurred at a composition of approximately 90 % Ni10 % Fe, and the maximum sens itivity occurred at approximately 80 % Ni20 % Fe, in accordance with l iterature values. In addition, both the application of an 80 mT magnet ic field during deposition and the annealing of samples at temperature s higher than the growth temperature of 200 degrees C improved the mag netic properties.