Application of various materials with negative saturation magnetostriction to vibration power generation

Various materials with negative saturation magnetostriction were applied to an U-shaped unimorph device for vibration power generation using inverse magnetostrictive effect. When a fcc Fe-Ni metal with the positive saturation magnetostriction was attached as an unimorph core to the front side of the U-shaped frame, larger values of the open circuit voltage V
op
were obtained in comparison with that of the frame core device without the sample. However, when a fcc Ni metal with the negative saturation magnetostriction was attached to the front side of the U-shaped frame, the V
op
value of this device was smaller than that of the frame core device. Larger V
op
values were obtained by attaching a fcc Ni metal to the back side of the U-shaped frame. Similar behaviors were observed in the devices using a bcc Fe metal and a 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.