The coupling of magnetostriction and magnetoresistance in elastic ferromagnetic composites with conducting matrix

An elastic ferromagnetic composite with a conducting matrix is described. T he composite consists of silicon steel particles of size 150-200 mu m and g raphite particles of size not exceeding 0.5 mu m dispersed in polymerized s ilicone. The resistivity of the composite amounted to (8.32-0.28) x 10(-3) Omega m and depended on its chemical constitution. The structure of the sys tem with a variable capacitance capacitor for a simultaneous measurement of magnetostriction and magnetoresistance of the produced composite is also d escribed. The measurements were carried out in a magnetic field with induct ion amounting to 0-8 T generated by a Bitter type magnet. It was found that in a field with induction of 8 T the composite exhibits, depending on its chemical composition, longitudinal magnetostriction (0.14-0.80) x 10(-2) an d relative longitudinal magnetoresistance 21.5-37.5%. After switching off t he field, a hysteresis of magnetostriction of (0.03-0.13) x 10(-2) and a hy steresis of magnetoresistance of 6-14% was observed. (C) 1999 Elsevier Scie nce S.A. All rights reserved.