Patent ID: 7851757

Claim:
A phase plate for an electron microscope, comprising: a support member having an opening; and a magnetic thin-wire ring or a magnetic thin-wire rod, a portion of the magnetic thin-wire ring or the magnetic thin-wire rod spanning the opening of the support member, so as to form a spanning portion having left and right sides, wherein the magnetic thin-wire ring or the magnetic thin-wire rod generates a vector potential, a phase difference is formed between electron beams that pass through the left and right sides of the spanning portion of the magnetic thin-wire ring or the magnetic thin-wire rod, the phase difference between the electron beams that pass through the left and right sides of the spanning portion of the magnetic thin-wire is controlled to a specific value by adjusting a value of saturation magnetization of the magnetic thin-wire, and the adjustment of the value of the saturation magnetization of the magnetic thin-wire is performed by temperature control.