Recent developments show that the exceptional physical, optical, magnetic, and electrical properties of spinel ferrite (SF) nanomaterials have now attracted the attention as high-density data storage materials, catalysts, gas sensors, rechargeable lithium batteries, information storage systems, magnetic bulk cores, adsorbents, magnetic fluids, microwave absorbers, and medical diagnostics. The aim of this review consists on an overview on the methods of preparation, the crystal structure and application of SFs used in technology for the design of new materials and devices. The chapter begins with a review of the different synthesis methods commonly used for the preparation of SFs. Then, the structural features of spinel unit cell, crystal chemical parameters, and extrinsic magnetic and optical properties are described in this chapter. Since the magnetism of SFs depends not only on particle chemistry and phase but also on the particle size and environment, the role of cationic distribution and ion exchange interaction are explored in determining the magnetic properties of the system. In addition, the potential applications of SFs in different fields of technology are also discussed.

Spinel Ferrite Nanoparticles: Synthesis, Crystal Structure, Properties, and Perspective Applications

Catalytic decomposition of sulfamethazine antibiotic and pharmaceutical wastewater using Cu-TiO2@functionalized SWCNT ternary porous nanocomposite: Influential factors, mechanism, and pathway studies

Tungsten–nitrogen (W–N) codoping has been known to enhance the photocatalytic activity of anatase TiO2 nanoparticles by utilizing visible light. The doping effects are, however, largely dependent on calcination or annealing conditions, and thus, the massive production of quality-controlled photocatalysts still remains a challenge. Using density functional theory (DFT) thermodynamics and time-dependent DFT computations (TDDFT), we investigate the atomic structures of N doping and W–N codoping in anatase TiO2, as well as the effect of the thermal processing conditions. We find that W and N dopants predominantly constitute two complex structures: an N interstitial site near a Ti vacancy in the triple charge state ((VTi-Ni)3–) and the simultaneous substitutions of Ti by W and the nearest O by N ((WTi-NO)+). The latter case induces highly localized shallow in-gap levels near the conduction band minimum (CBM) and the valence band maximum (VBM), whereas the (VTi-Ni)3– defect complex yielded deep levels (1.9 eV a...

Simultaneously Controllable Doping Sites and the Activity of a W–N Codoped TiO2 Photocatalyst

Dielectric properties and thermal behavior of electrolytic manganese anode mud in microwave field.

Effect of nickel substitutions on some properties of Cu–Zn ferrites

Thermodynamic properties of Mn3O4, Mn2O3 and MnO2 are reassessed based on new measurements and selected data from the literature. Data for these oxides are available in most thermodynamics compilations based on older calorimetric measurements on heat capacity and enthalpy of formation, and high-temperature decomposition studies. The older heat capacity measurements did not extend below 50 K. Recent measurements have extended the low temperature limit to 5 K. A reassessment of thermodynamic data was therefore undertaken, supplemented by new measurements on high temperature heat capacity of Mn3O4 and oxygen chemical potential for the oxidation of MnO1-x, Mn3O4, and Mn2O3 to their respective higher oxides using an advanced version of solid-state electrochemical cell incorporating a buffer electrode. Because of the high accuracy now achievable with solid-state electrochemical cells, phase-equilibrium calorimetry involving the ``third-law'' analysis has emerged as a competing tool to solution and combustion calorimetry for determining the standard enthalpy of formation at 298.15 K. The refined thermodynamic data for the oxides are presented in tabular form at regular intervals of temperature.

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G. Rajitha

Papers

Thermodynamic Data for Mn3O4, Mn2O3 and MnO2

Thermodynamic properties of strontium titanates: Sr2TiO4, Sr3Ti2O7, Sr4Ti3O10, and SrTiO3

Nonstoichiometry, defects and thermodynamic properties of YFeO3, YFe2O4 and Y3Fe5O12

Discussion of enthalpy, entropy and free energy of formation of GaN

Stress sensitivity of inductance in NiCuZn ferrites