Absolute calibration of low- and high-field magnetic susceptibilities using rare earth oxides

Abstract

Low‐ or high‐field magnetic susceptibility measurements have been routinely utilized in or even beyond paleomagnetism and environmental magnetism. Susceptibility meters, such as Bartington or Kappabridge, are now commercially available and have enabled us to measure a variety of samples readily. However, interlaboratory or interinstrument calibration is not yet faithfully performed on absolute or even relative scales. The reason is that no standard material is generally accepted for susceptibility calibration. Gadolinium or other rare earth oxides are considered as ideal standard materials because of the high chemical stability. We defined reference susceptibility values for all available paramagnetic rare earth oxides after carefully examining the Landolt‐Börnstein database and selected four compounds Nd2O3, Gd2O3, Dy2O3 and Er2O3 as standard materials. We carried out calibration measurements using Bartington and Kappabridge susceptibility meters, a Magnetic Property Measurement System (Quantum Design) and a Vibrating Sample Magnetometer (Princeton Measurements Corporation). Linear relationships between measured and reference values were observed for all the instruments. In some cases, however, measured values deviated significantly from expected values, suggesting that calibration is indeed necessary. If any instrument is calibrated with these rare earth oxides, we can reliably compare absolute susceptibility values measured with any kind of instrument in different laboratories.

Reconstruction of superparamagnetic particle grain size distribution from Romanian loess using frequency dependent magnetic susceptibility and temperature dependent Mössbauer spectroscopy

“…The value of magnetic susceptibility for the Dy 2 O 3 sample should be the same on every working frequency. We set this value to 3.07 × 10 −6 m 3 /kg as reference for calibration (mass susceptibility at room temperature (RT) as calculated by Fukuma and Torii, 2011). According to the manufacturer's recommendation we made five to ten measurements of the calibration sample at each frequency and based on the reference value a calibration constant for each measuring frequency was determined.…”

A Gallium-Based Magnetocaloric Liquid Metal Ferrofluid

“…The gadolinium particles are not oxidized and do not feature an oxide shell within the liquid metal due to the oxygen-free and overall reducing conditions within galinstan. The magnetic nature of the developed ferrofluids provides further evidence toward the gadolinium being present as elemental Gd nanoparticles, because Gd 2 O 3 is paramagnetic . TEM analysis of the 2.3 wt % Gd sample revealed a smaller average particle size of 6.9 ± 1.7 nm (Figure S3).…”

“…The magnetic nature of the developed ferrofluids provides further evidence toward the gadolinium being present as elemental Gd nanoparticles, because Gd 2 O 3 is paramagnetic. 28 TEM analysis of the 2.3 wt % Gd sample revealed a smaller average particle size of 6.9 ± 1.7 nm (Figure S3). We attribute the difference in particle size between these two samples to ripening processes because the 2.3 wt % sample was prepared fresh whereas the 1.2 wt % sample was analyzed approximately 4 weeks after the initial preparation.…”

Dysprosium oxide and dysprosium-oxide-doped titanium oxide thin films grown by atomic layer deposition

“…Dysprosium and dysprosium oxide have been materials of interest for a long time [1][2][3][4][5][6][7][8][9] as dysprosium is a lanthanide metal with the largest magnetic moment and susceptibility. 2 In addition, combination of polymeric architectures with dysprosium ions can produce hybrid materials with extremely rich properties.…”

“…Dysprosium oxide has been considered as a candidate of high-permittivity (high-k) capacitor dielectric for nonvolatile memory applications 3 and as a high-k gate dielectric. [4][5][6] Regarding the performance of Dy 2 O 3 as essentially a paramagnetic oxide, standards in the form of Dy 2 O 3 powders have been exploited for quantum interference magnetometer, 7 vibrating sample magnetometer (VSM), 8 or in the form of small single crystals as additive seeds for superconducting materials for a susceptometer. 9 Dysprosium-doped polymers and glasses can emit white light, 10,11 while Dy:PbGa 2 S 4 compound has been shown to be a solid state laser material emitting at 4.32 lm when pumped by 1.7 lm laser diodes.…”