Squid vsm

The magnetic properties of the Zr-16Nb-xTi alloys were measured by employing a SQUID-VSM device (superconducting quantum interference device-vibrating sample magnetometer, Quantum Design, San Diego, CA, USA) at room temperature. The specimen magnetization (M) and applied magnetic field (H) were recorded. By taking the magnetization (M) as the y-axis and magnetic field (H) as the x-axis, the slope of the obtained magnetization curve was denoted as the magnetic susceptibility $\left(\mathsf{\chi }\right)$ . $\mathsf{\chi }=\mathrm{M}/\mathrm{H}$ .
An applied magnetic field (H) was set from −30,000 Oe to +30,000 Oe, which is consistent with the magnetic field used for clinical MRI detection (3T).

¹H and ¹³C NMR spectra for compounds were obtained in DMSO-d₆, using a Bruker AMX-500 NMR spectrometer. Transmission electron microscopy (TEM) images were obtained on a HITACHI H-7000 FA transmission electron microscope. High-resolution mass spectrometry (HR MS–ESI) spectra were recorded on a Bruker micro TOF-Q instrument. The magnetic properties were measured at 300 K with a vibrating sample magnetometer (SQUID-VSM, Quantum Design, American). In vitro fluorescence images of cells were recorded on a confocal laser scanning microscope (CLSM, Nikon, Japan). The surface areas were measured by an ASAP-2020 physisorption apparatus (Micromeritics, American). The UV–Vis absorption spectra were determined by an Evolution 220 spectrophotometer (Thermofisher Scientific). The size distributions and zeta potentials were measured by a Malvern Zetasizer 90. The metal contents in cells and tissues were tested by ICP-MS (FLEXAR NEXLON300X).

The magnetic properties of the nanoparticles were measured using a commercial magnetic property measurement system (SQUID-VSM, Quantum Design). For the field-cooling (FC) loops and the training effect measurements, the samples were cooled from 380 K to the required temperature under 65 kOe magnetic field, and the data were recorded thereafter under 50 kOe. It should be noted that such FC process is a little different from the typical process in conventional exchange bias measurement that is usually established by cooling the samples through T_N. Here, the BFO nanoparticle is cooled from the maximum temperature 380 K of the instrument, which is much smaller than T_N of BFO. Such decreased onset temperature may decrease the value of exchange bias field but does not affect its variation with temperature. Meanwhile, in order to ensure that there is no trapped flux, samples and superconducting magnet were demagnetized slowly with oscillating field before each measurement.

Measurements were performed at 300 K from ± 5,570 kA/m (±70,000 Oe) and at 5 K from ± 5,570 kA/m (±70,000 Oe) using a superconducting quantum interference device with vibrating sample magnetometer (SQUID VSM) (Quantum Design, Inc). The 5 K data were measured after cooling either in zero applied magnetic field or in the presence of an applied magnetic field of 5.6 MA/m (70,000 Oe). Samples were loaded into Kel-F liquid capsules (LakeShore Cryogenics), and sealed with epoxy to preserve water during measurement under vacuum. Data are normalized to either total iron content, determined by ferene-s method previously described^{60 (link)}, or by total solid content.

Polycrystalline samples of BMTO were prepared by a conventional solid state method. Prior to use, we preheated BaCO ${}_3$ (Alfa Aesar, 99.997 %), MnO ${}_2$ (Alfa Aesar, 99.996 %) and TeO ${}_2$ (Alfa Aesar, 99.9995 %) to remove any moisture. The appropriate stoichiometric mixtures were pelletized and sintered at 1200 ${}^{\circ }$ C for 30 hours with several intermittent grindings. The phase purity was confirmed by the Rietveld refinement of XRD taken on a smartLAB Rigaku X-ray diffractometer with Cu $\mathcal{K}\alpha$ radiation ( $\lambda$ = 1.54 Å). Magnetization measurements were carried out using a Quantum Design SQUID VSM in the temperature range 5 K $\le \mathit{T}\le$ 340 K under magnetic fields 0 T $\le {\mu }_{0}H\le$ 7 T. Specific heat measurements were performed on a Quantum Design Physical Properties Measurement System (QD, PPMS) by thermal relaxation method, in the temperature range 2 K $\le \mathit{T}\le$ 240 K. $\mu$ SR measurements were performed using the GPS spectrometer at the Paul Scherrer Institute, Villigen, Switzerland, on a 1-g powder sample in the temperature range 1.6 K $\le$
T $\le$ 50 K. The sample was put on a “fork” sample holder and the veto mode was employed, which ensured negligible background signal, as evidenced by the vanishing amplitude of the signal recorded in weak transverse field below $T_N$ ( $\sim 1\%$ of the full signal; Fig. 4). The transverse muon-polarization was used in zero applied field (ZF) and in a weak transverse field (TF) of 5 mT.

Static magnetic measurements were performed at room temperature using a superconducting quantum interference device (SQUID-VSM, Quantum Design, USA), with the magnetic hysteresis loops measured along the in-plane easy and hard axes to a maximum field of 3 Tesla. Microwave property measurements were carried out using a broadband frequency-swept FMR spectrometer with a flip-chip configuration44 (link)55 , in which the BaM film was positioned face-down on a coplanar waveguide. The transmission responses of the coplanar waveguide were detected using a vector network analyzer (VNA) Agilent E8361 C at varied direct current (DC) magnetic field, with the in-plane easy axis (c-axis) of the film sample applied parallel to the applied DC magnetic field. The transmission coefficient S₂₁ was measured at a constant field with the background subtraction positioned off without an applied magnetic field. This test method was adopted to obtain high-quality data for ferromagnetic resonant (FMR) frequency and minimize interference from other sources of absorption.

The structures of the MMIPs were characterized by FT-IR, TEM, particle size analysis, and VSM. The structures of the CDs and CDs@VPA were characterized by FT-IR, UV-Vis, and TEM. Meanwhile, CDs were characterized by XPS. FT-IR spectra (4000–400 cm⁻¹) were obtained via a Nicolet 6700 FT-IR spectrometer (Thermo Fisher Scientific, Boston, MA, USA). TEM (Tecnai G2 F20, FEI, Nashville, TN, USA) was used to observe diameter and morphology of particles, which compared with the results from particle size analysis (Nanoparticle size and Zeta potential analyzer, Malvern ZS90, London, UK). The magnetic property was measured at room temperature using VSM (Squid-VSM, Quantum Design, Atlanta, GA, USA). UV-Vis spectra was scanned and recorded on an UV2800 ultraviolet-visible spectrophotometry (Sunny Hengping Scientific Instrument Co., Ltd., Shanghai, China). XPS (Thermo Scientific Escalab 250Xi, Boston, MA, USA) was used to study the composition of substances.