title: Tiny adiabatic-demagnetization refrigerator for a commercial superconducting quantum interference device magnetometer.
abstract: A tiny adiabatic-demagnetization refrigerator (T-ADR) has been developed for a commercial superconducting quantum interference device magnetometer [Magnetic Property Measurement System (MPMS) from Quantum Design]. The whole T-ADR system is fit in a cylindrical space of diameter 8.5 mm and length 250 mm, and can be inserted into the narrow sample tube of MPMS. A sorption pump is self-contained in T-ADR, and hence no complex gas handling system is necessary. With the single crystalline Gd3Ga5O12garnet (∼2 g) used as a magnetic refrigerant, the routinely achievable lowest temperature is ∼0.56 K. The lower detection limit for a magnetization anomaly is ∼1 × 10-7emu, estimated from fluctuation of the measured magnetization. The background level is ∼5 × 10-5emu below 2 K at H = 100 Oe, which is largely attributable to a contaminating paramagnetic signal from the magnetic refrigerant.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
authors.forename: Taku J
authors.initials: TJ
authors.lastname: Sato
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Okuyama
authors.affiliation: National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Kimura