Magnetic properties of yttrium iron garnet polycrystalline material prepared by spray-drying synthesis

The yttrium iron garnet polycrystalline powder was prepared by spry-drying synthesis from nitrates solution. The calcined powder was pressed into pellets and sintered at various temperatures for 2 hours. Prepared samples were characterized by XRD analysis and magnetic properties were measured. The magnetic moment of 4.3 µB and saturation magnetization of 24 Am2kg-1were observed for sample sintered at 1000 °C

Experimental Liver Iron Measurement with the SQUID Gradiometer System

An experimental system for noninvasive measurement of the iron stores in the liver of living human organism has been designed and realized. This system enables to test the presence and to determine the iron concentration in this organ. The principle of operation is based on measurement of small response (magnetic moment) of the paramagnetic protein ferritin to the applied magnetic field on the complex diamagnetic background of other body organs. The experiment was performed by modified SQUID system with the 2nd order gradiometer. At present, the sensitivity of the system is 1 mg Fe per gram of the wet liver, which from the point of view of clinical diagnostics, enables to indicate the state of the liver iron overload, e.g., in hemochromatosis and hemosiderosis

Magnetometric Measurements of Low Concentration of Coated Fe3O4Fe_{3}O_{4} Nanoparticles

A modified RF SQUID system with the $2^{nd}$ order gradiometer has been tested for the purposes of detecting the magnetic nanoparticles as potential carriers of biological medicament. The paper presents basic information about the sensitivity of the system and its use for quantification of low concentration of coated $Fe_{3}O_{4}$ magnetic nanoparticles. Model measurements provided information that enabled us to define the parameter influencing the experimental results. The volume of the biological object and its distance from the antenna appear to have the significant influence on the measurement accuracy

Effects of Gd/Ba Nonstoichiometry in Gd1+xBa2−xCu3O7−δGd_{1+x}Ba_{2-x}Cu_{3}O_{7-δ} on Superconducting and Magnetic Properties

Effects of slight nonstoichiometry in $Gd_{1+x}Ba_{2-x}Cu_{3}O_{7-δ}$ compounds on superconducting and magnetic properties were studied. The series of single-phase samples of $Gd_{1+x}Ba_{2-x}Cu_{3}O_{7-δ}$ with composition deviation x from the stoichiometric value of 0 to 0.1 and to -0.1 were synthesized by the solid-state reaction method from $Gd_{2}O_{3}$, $BaCO_{3}$ and CuO precursors, sintered at the temperature of ~ 1000°C in flowing oxygen and annealed at 450°C for 24 h

Magnetic Properties of V2O3V_{2}O_{3} Nanooxide Prepared Mechanochemically With and Without Salt Matrix

We present a new technological route of synthesis of $V_{2}O_{3}$ nanocrystals based on mechanochemical reduction of $V_{2}O_{5}$ with $Na_{2}SO_{3}$ as a reductant, followed by low temperature vacuum annealing. The structural and magnetic properties of the $V_{2}O_{3}$ nanocrystals were studied

Magnetic Studies of EuBa2Cu3−xRuxO7−δEuBa₂Cu_{3-x}RuₓO_{7-δ} Compounds

Effects of Ru addition on magnetic properties of $EuBa₂Cu_{3-x}RuₓO_{7-δ}$ compounds were studied. Samples of $EuBa₂Cu_{3-x}RuₓO_{7-δ}$ with x from 0.00 to 0.70 were prepared by the solid state reaction technique from Eu₂O₃, BaCO₃, CuO and RuO₂ precursors. Temperature dependences of the zero-field cooled (ZFC) and the field cooled (FC) DC magnetic moment at low and high applied magnetic field Hₐ were measured by the QD SQUID magnetometer MPMS XL-7 and AC magnetization $M_{AC}(H)$ curves at 77 K by the compensation method using the second-order SQUID gradiometer. The molar susceptibility χ of the samples was corrected to the effects of the sample holder and diamagnetism and χ* also was corrected to the temperature independent paramagnetic/diamagnetic contribution $χ^{TN}$ and fitted by the Curie-Weiss relation. The values of the Weiss temperature and the effective magnetic moment have been estimated at low and high value of applied magnetic field

Effects of Ru Addition on the Superconducting Properties of the Eu-123 System

Effects of the Ru addition on the structural and superconducting properties of the Eu-123 system were studied. Samples of the nominal composition $EuBa₂Cu_{3-x}Ru_{x}O_{7-δ}$ with x ranging from 0.0 to 0.7 were prepared by the solid state reaction technique from Eu₂O₃, BaCO₃, CuO and RuO₂ precursors at the temperature of 1050°C for 72 h in flowing oxygen and oxygen-annealed at 580°C for 24 h. X-ray diffraction data show the presence of another Ba-Eu-Ru-O phase, for x ≥ 0.03, in addition to the main superconducting phase. AC and DC magnetization characteristics were measured by the compensation method using the second-order SQUID gradiometer at ≈ 77 K and the QD SQUID magnetometer MPMS XL-7 at 20 K. The superconducting properties, $T_{c}$, $ΔT_{c}$, change only weakly up to x = 0.2, and magnetization M(H) deteriorates with an increasing Ru content