Application of Various Materials With Negative Saturation Magnetostriction to Vibration Power Generation

Various materials with negative saturation magnetostriction were applied to a U-shaped unimorph device for vibration power generation using an inverse magnetostrictive effect. When an fcc Fe–Ni alloy with the positive saturation magnetostriction was attached as an inverse magnetostrictive material on the front side of a U-shaped frame, larger values of the open-circuit voltage
$V_{\mathrm {op}}$
were obtained in comparison with that of the frame core device without a sample. However, when an fcc Ni metal with the negative saturation magnetostriction was attached on the front side of the U-shaped frame, its
$V_{\mathrm {op}}$
value was almost the same as that of the frame core device. Larger
$V_{\mathrm {op}}$
values were obtained by attaching the fcc Ni metal on the back side of the U-shaped frame. Similar characteristics were observed in the devices using a bcc Fe metal and an hcp Co metal with negative saturation magnetostriction. Therefore, the back side setting is effective for the application of materials with negative saturation magnetostriction to the U-shaped unimorph device.