電磁歪効果と磁気誘導圧電気効果

抄録

Unusually large deformation coefficients were observed by applied electric fields in conducting Mn-Zn ferrite crystals. The observed electrostrictive coefficients (X) defined by S=1/2_XE² (S: strain, E: electric field) were of the order of magnitude of 10^-10(m/V)², which were 10¹¹ times larger than the electrostrictive coefficient of BaTiO³. The observed strains are due to a magnetostrictive effect from the magnetic field induced by the electric current through the crystal. The electric signals due to elastic strains were obtained by using a dc biasing current.
A large piezoelectric effect was also observed in the same Mn-Zn ferrite crystals under magnetic fields both parallel to and perpendicular to the electric field. The induced strains were correctly given by the relation: S=d•E, The piezoelectric d-constants were dependent upon the magnetic field and crystallographic orientations and were of the order of magnitude of 10^-10 C/N under a suitable magnetic field. These are, respectively, about 100 times larger than and of the same order of magnitude as the piezoelectric constant of a quartz crystal and a PZT ceramic element.
The emf voltages due to elastic strains were obtained as a result of the inverse processes mentiond above.