Calibration of ac and dc magnetometers with a Dy{sub 2}O{sub 3} standard

Journal Article · Fri Apr 15 04:00:00 EDT 2011 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3581224· OSTI ID:22062307

Chen, D -X; Skumryev, V ^[1]; Bozzo, B ^[2]

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1. ICREA and Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)
2. Institut de Ciencia de Materials de Barcelona, CSIC, 08193 Bellaterra, Barcelona (Spain)

The ac susceptibility and magnetization curves of a glued Dy{sub 2}O{sub 3} powder sample are measured by an ac susceptometer and a dc superconducting quantum interference device magnetometer, both of which have been calibrated previously. It is shown that the magnetic moment of the paramagnetic sample as a function of field and temperature may be accurately expressed by a combination of the Curie-Weiss law and the Langevin function at T > 45 K with three adjusting parameters, so that the dc magnetization curves and the magnitude and phase of ac susceptibility at different values of dc bias field measured by any magnetometer can be calibrated by using Dy{sub 2}O{sub 3} as a standard. The expressions are empirical and cannot be justified in the entire field and temperature range by existing theories of paramagnetism. Below 10 K, indication of approaching a possible phase transition is found. It is shown that pure Dy{sub 2}O{sub 3} powder may be used as a primary standard, with susceptibility [13.28(T+ 17)]{sup -1} emu/Oe/g at T > 50 K and H < 10 kOe, in consistency with the Curie-Weiss law and the quantum mechanical theory of paramagnetism.

• OSTI ID: 22062307
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 4 Vol. 82; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
CALIBRATION
CURIE-WEISS LAW
DYSPROSIUM OXIDES
MAGNETIC MOMENTS
MAGNETIZATION
MAGNETOMETERS
PARAMAGNETISM
PHASE TRANSFORMATIONS
QUANTUM MECHANICS
SQUID DEVICES
TEMPERATURE DEPENDENCE