title: High temperature superconductor micro-superconducting-quantum-interference-device magnetometer for magnetization measurement of a microscale magnet.
abstract: We have developed a high temperature superconductor (HTS) micrometer-sized dc superconducting quantum interference device (SQUID) magnetometer for high field and high temperature operation. It was fabricated from YBa2Cu3O7-delta of 92 nm in thickness with photolithography techniques to have a hole of 4x9 microm2 and 2 microm wide grain boundary Josephson junctions. Combined with a three dimensional magnetic field coil system, the modulation patterns of critical current Ic were observed for three different field directions. They were successfully used to measure the magnetic properties of a molecular ferrimagnetic microcrystal (23x17x13 microm3), [Mn2(H2O)2(CH3COO)][W(CN)8]2H2O. The magnetization curve was obtained in magnetic field up to 0.12 T between 30 and 70 K. This is the first to measure the anisotropy of hysteresis curve in the field above 0.1 T with an accuracy of 10(-12) J T(-1) (10(-9) emu) with a HTS micro-SQUID magnetometer.
authors: Institute for Solid State Physics, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa-shi, Chiba 277-8581, Japan. ktakeda@issp.u-tokyo.ac.jp
authors: Keiji
authors: K
authors: Takeda
authors: Hatsumi
authors: H
authors: Mori
authors: Akira
authors: A
authors: Yamaguchi
authors: Hidehiko
authors: H
authors: Ishimoto
authors: Takayoshi
authors: T
authors: Nakamura
authors: Shinya
authors: S
authors: Kuriki
authors: Toshiya
authors: T
authors: Hozumi
authors: Shin-ichi
authors: S
authors: Ohkoshi