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Structural and magnetic properties of NiCr1.7Fe0.3O4 nanoparticles, synthesized by a facile coprecipitation method, are examined using temperature‐dependent X‐ray diffraction, neutron scattering with XYZ polarizations, and magnetic measurements. The structural analysis demonstrates the stabilization of the cubic phase down to 200 K, followed by a low‐temperature tetragonal phase at 100 K and an orthorhombic phase below 50 K. The refined occupancies of cations demonstrate that the NiCr1.7Fe0.3O4 is a mixed spinel compound, wherein B sites are populated by ≈85% Cr3+ and ≈15% Ni2+ cations and A sites are populated by ≈70% Ni2+ and ≈30% Fe3+ cations. As a consequence, the reduction in the occupancy of Jahn–Teller active Ni2+ (triply degenerate: e4 t4) at A site is attributed to the stabilization of the cubic phase below room temperature. Temperature‐dependent magnetization and neutron scattering with XYZ polarizations measurements reveal the ferrimagnetic nature of the magnetic phase and the absence of spin‐spiral ordering in NiCr1.7Fe0.3O4 nanoparticles. Furthermore, field‐dependent magnetization measurement demonstrates an exchange bias field of ≈134.5 kA m−1 at 5 K. The training effect measurement is performed to discuss the origin of exchange bias based on different phenomenological models such as power‐law and multiexponent models. [ABSTRACT FROM AUTHOR]

Herein, the strontium bioactive glass with ferrite composites is studied for the application of biocompatibility and magnetic hyperthermia. The bioactive glass SrBG (46.1SiO2–21.9CaO–24.4Na2O–2.6P2O5–5SrO) prepared by the melt quench technique at 1400 °C and manganese ferrite (MnFe2O4) prepared by the modified microwave reflux oven are mixed together and sintered at 400 °C for 6 h for making composites. The in vitro bioactivity of these composites is observed by immersing in simulated body fluid (SBF). The growth of the precipitated hydroxyapatite phase observed after SBF treatment is confirmed by the X‐ray diffractometer (XRD), Fourier transform infrared (FTIR) spectrometer, and scanning electron microscope (SEM) results. The in vitro cell viability assessment of these composites with MG‐63 cell lines indicates that the composites are biocompatible in nature. Furthermore, these composites show the antibacterial effect on the E. coli and S. Aureus bacteria cells. The room temperature superparamagnetic behavior accompanied by the heating ability in these composites proves their potential role for hyperthermia applications. [ABSTRACT FROM AUTHOR]