Mpms xl squid magnetometer

The Centre Régional de Mesures Physiques de l’Ouest (Rennes) performed the elemental analyses of the compounds. The dc magnetic susceptibility measurements were performed on solid polycrystalline samples with a Quantum Design MPMS-XL SQUID magnetometer between 2 and 300 K in applied magnetic fields of 200 Oe, 2000 Oe and 10,000 Oe for the 2–20, 20–80 K and 80–300 K temperature ranges, respectively. The microcrystallites are immobilized in a pellet made with Teflon tape. Quantum Design PPMS magnetometers were used to measure the ac magnetic susceptibility for frequencies between 10 and 10 kHz. Finally, these measurements were all corrected for the diamagnetic contribution, as calculated with Pascal’s constants.

Quantification of the inorganic magnetic nickel nanowire material present in different organs explanted from exposed mice was carried out by assessing the total magnetic signal collected from each organ sample. Magnetization measurements were made at room temperature using a Quantum Design MPMS XL SQUID magnetometer (Quantum Design, Inc., CA, USA). Same volume of organ samples was loaded into gel capsules mounted in a non-magnetic straw. All measurements were made using a standard second-order gradiometer, around the maximum slope position of the second derivative curve, with no auto-tracking of the actual sample position. Prior and post measurement empty and full capsules were weighted (Model AX26DR, Mettler Toledo, USA) in order to then calculate the total magnetic nickel nanowire material mass against the full sample mass. Total mass of magnetic nickel nanowire material was calculated from the magnetisation measurement carried out compared to the magnetisation saturation of the same weight mass of magnetic bulk nickel powder, which as a magnetisation saturation of 55.4 A·m²/kg.

Magnetic susceptibility of the polycrystalline samples of complexes [Cu(hfac)₂(3a)₂] and [Cu(hfac)₂(3b)₂] was measured with a Quantum Design MPMSXL SQUID magnetometer in the temperature range 2 to 300 K with a magnetic field of up to 5 kOe. Diamagnetic corrections were made via the Pascal constants. The effective magnetic moment was calculated as μ_eff(T) = [(3k/N_Aμ_B²)χT]^1/2 ≈ (8χT)^1/2.

UV–vis–NIR spectra were measured in KBr pellets on
a PerkinElmer Lambda 1050 spectrometer in the 250–2500 nm range.
EPR spectra were recorded for the polycrystalline samples of 1 and 2 with a JEOL JES-TE 200 X-band ESR spectrometer
equipped with a JEOL ES-CT470 cryostat. A Quantum Design MPMS-XL SQUID
magnetometer was used to measure the static magnetic susceptibility
of 1 at a 1 kOe magnetic field in cooling and heating
conditions in the 300–1.9 K range. The sample-holder contribution
and core temperature-independent diamagnetic susceptibility (χ_d) were subtracted from the experimental values. The χ_d values were estimated from the extrapolation of the data
in the high-temperature range by fitting the data with the following
expression: χ_M = C/(T – Θ) + χ_d, where C is the Curie constant and Θ is
the Weiss temperature. Effective magnetic moments (μ_eff) were calculated with the formula μ_eff = (8χ_MT)^1/2.

Electrical resistivity and Hall measurements were carried out from 0.4 K to 300 K in applied magnetic fields up to 9 T using a conventional ac four-point technique implemented in a Quantum Design PPMS platform. Dimensions of samples were: 0.010 × 0.051 × 0.227 cm³, for ρ_xx, and 0.0067 × 0.051 × 0.1524 cm³ for ρ_xy measurements. Current and voltage leads were 50 μm thick silver wires attached to the parallelepiped-shaped specimens with silver paste and additionally spot welded. The heat capacity was measured on 10.6 mg collection of single crystals, in the temperature interval 0.4–5 K by relaxation time method using also the PPMS platform. DC magnetization and AC magnetic susceptibility measurements were performed on 30.1 mg collection of single crystals, in the temperature range 1.62–2.6 K in weak magnetic fields up to 2 mT employing a Quantum Design MPMS-XL SQUID magnetometer.

Mouse tissue was freeze-dried overnight and all the organs (except the liver) were transferred directly to gelatin capsule sample holders for magnetic characterization. Given the large volume of the liver, this organ was ground in a mortar to obtain a homogenous powder and an aliquot (≈ 100 mg) of this powder was then placed inside a gelatin capsule for magnetic characterization. The temperature dependence of the AC magnetic susceptibility was measured using a QuantumDesign MPMS-XL SQUID magnetometer, using the AC option, a field amplitude of 326 A/m and a frequency of 11 Hz. Measurements were made over the temperature range of 2–350 K to identify and quantify the ferritin and MNPs present in the tissues. In addition, measurements were taken from other samples in the 200–250 K temperature range to locate the MNP maxima signal in out-of-phase magnetic susceptibility (χ″), or in the 2–40 K temperature range to locate ferritin.
The agar suspensions of the injected MNPs (see MNP physicochemical characterization section) and a mouse ferritin sample [45 (link)] were used as standards to quantify both species using the height of the AC susceptibility maxima, as described previously [42 (link)].