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Herein we report the effect of samarium (rare earth metal) doping on the morphological, structural, optical, magnetic, dielectric, and electrical properties of copper–iron oxide ferrite composites [CuFe2−xSmxO4 (x = 0, 0.05, 0.075, and 0.1)] (abbreviated as SCFO). The CuFe2−xSmxO4-based ferrites were synthesized by the solution combustion technique. The morphological and structural features and elemental composition of these doped ferrites were characterized by scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy. The analysis revealed improved structural features for (Sm3+)-doped copper–iron oxide ferrites and the formation of a homogeneous composite structure. Doping of a rare earth metal (Sm3+) into the Cu–Fe–O ferrite significantly enhanced the room-temperature electrical conductivity of the doped ferrite in comparison to its pure counterpart. The energy band gap value of the higher-concentration sample was found to decrease significantly in comparison to the pure ferrite due to enhanced charge density across the grain boundaries. Further, it was observed that (Sm3+) doping led to improved optical, magnetic, and dielectric response of the doped ferrites which was dependent on the concentration of the dopant. The dielectric constant of these doped ferrites was found to be higher at lower frequencies and decreased dramatically with increased frequencies due to the greater dielectric dispersion as well as electron hopping in the higher-frequency region. The magnetic properties showed strong dependence on both the sintering temperature and concentrations of (Sm3+) doping. The optical bandgap decreased significantly with the increase in concentration of (Sm3+) doping. In light of the ease of synthesis, improved electrical conductivity, and dielectric, magnetic, and optical properties, these SCFO ferrites hold promise as a potential material for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Comprehension of chemical bonding and its intertwined relation with charge carriers and heat propagation through a crystal lattice is imperative to design compounds for thermoelectric energy conversion. Here, we report the synthesis of large single crystal of new p‐type cubic AgSnSbTe3 which shows an innately ultra‐low lattice thermal conductivity (κlat) of 0.47–0.27 Wm−1 K−1 and a high electrical conductivity (1238 – 800 S cm−1) in the temperature range 294–723 K. We investigated the origin of the low κlat by analysing the nature of the chemical bonding and its crystal structure. The interaction between Sn(5 s)/Ag(4d) and Te(5p) orbitals was found to generate antibonding states just below the Fermi level in the electronic band structure, resulting in a softening of the lattice in AgSnSbTe3. Furthermore, the compound exhibits metavalent bonding which provides highly polarizable bonds with a strong lattice anharmonicity while maintaining the superior electrical conductivity. The electronic band structure exhibits nearly degenerate valence‐band maxima that help to achieve a high Seebeck coefficient throughout the measured temperature range and, as a result, the maximum thermoelectric figure of merit reaches to ≈1.2 at 661 K in pristine single crystal of AgSnSbTe3. [ABSTRACT FROM AUTHOR]

Comprehension of chemical bonding and its intertwined relation with charge carriers and heat propagation through a crystal lattice is imperative to design compounds for thermoelectric energy conversion. Here, we report the synthesis of large single crystal of new p‐type cubic AgSnSbTe3 which shows an innately ultra‐low lattice thermal conductivity (κlat) of 0.47–0.27 Wm−1 K−1 and a high electrical conductivity (1238 – 800 S cm−1) in the temperature range 294–723 K. We investigated the origin of the low κlat by analysing the nature of the chemical bonding and its crystal structure. The interaction between Sn(5 s)/Ag(4d) and Te(5p) orbitals was found to generate antibonding states just below the Fermi level in the electronic band structure, resulting in a softening of the lattice in AgSnSbTe3. Furthermore, the compound exhibits metavalent bonding which provides highly polarizable bonds with a strong lattice anharmonicity while maintaining the superior electrical conductivity. The electronic band structure exhibits nearly degenerate valence‐band maxima that help to achieve a high Seebeck coefficient throughout the measured temperature range and, as a result, the maximum thermoelectric figure of merit reaches to ≈1.2 at 661 K in pristine single crystal of AgSnSbTe3. [ABSTRACT FROM AUTHOR]

For the first time, innovative and remarkable humidity sensing properties of solvent combustion produced spinel cobalt chromite nanoparticles based microporous materials have been presented. These features were identified by solution combustion. To create a capacitive humidity sensor, microporous samples were initially created by sintering a green tape of cobalt chromite that had been manufactured via tape casting. To finish the process, the samples were sandwiched between two parallel silver electrodes. The newly developed sensors have good humidity sensing capabilities over a wide range of relative humidity (RH), from 11 to 97%, with a detectable gain of 3 pF/%RH. Because of the significant rise in dielectric constant, the sensing properties can be attributed to the dielectric polarisation of moisture molecules that are absorbed on the surface of the CoCr2O4 material and then condensed in the surface pores. A variety of complicated tests have been performed in order to get a knowledge of its physicochemical properties. These investigations resulted in the sensor’s remarkable moisture detection abilities. [ABSTRACT FROM AUTHOR]

In the present work, Co(1−x)BixCr2O4 (where x = 0.00, 0.05, and 0.10) nanoparticles were investigated in detail by combining theoretical and experimental efforts. The Co(1−x)BixCr2O4 (where x = 0.00, 0.05, and 0.10) nanoparticles were synthesized via a solution combustion method and studied through structural, microstructural, electrical, and magnetic analysis complemented by DFT calculations. The structural analysis confirmed a single-phase spinel cubic structure with singular structural distortions associated with Bi-doping and the generation of metal vacancies. The nanoparticles mainly enclosed the (100), (110), and (311) surfaces of the cubic spinel chromite structure, resulting in under-coordinated Co, Cr and Bi centers along their exposed surfaces. The dielectric parameters were explained using Koop's phenomenological theory, Maxwell-Wanger theory, and thermal energy of the vibrations, highlighting the role of Bi-doping in controlling the ferroic orders for the Co(1−x)BixCr2O4 nanoparticles. Moreover, the magnetic analysis indicated a paramagnetic to long-range collinear ferrimagnetism transition at the Curie temperature and non-collinear ferrimagnetism at the spiral transition temperature. These transitions are associated with the exchange coupling constants, as evaluated by DFT calculations before and after Bi-doping. Indeed, the effect of Bi-doping on the magnetic properties was determined to be a reduction in superficial magnetism, resulting in a diminished magnetization value for the doped samples, which is attributed to the major exposure of the (110) and (311) surfaces. Furthermore, the investigation of the morphological modulation of Co(1−x)BixCr2O4 nanoparticles through this innovative and unified procedure can guide other experimental studies in the rational design of superior multiferroic nanoparticles. [ABSTRACT FROM AUTHOR]

Comprehension of chemical bonding and its intertwined relation with charge carriers and heat propagation through a crystal lattice is imperative to design compounds for thermoelectric energy conversion. Here, we report the synthesis of large single crystal of new p‐type cubic AgSnSbTe3 which shows an innately ultra‐low lattice thermal conductivity (κlat) of 0.47–0.27 Wm−1 K−1 and a high electrical conductivity (1238 – 800 S cm−1) in the temperature range 294–723 K. We investigated the origin of the low κlat by analysing the nature of the chemical bonding and its crystal structure. The interaction between Sn(5 s)/Ag(4d) and Te(5p) orbitals was found to generate antibonding states just below the Fermi level in the electronic band structure, resulting in a softening of the lattice in AgSnSbTe3. Furthermore, the compound exhibits metavalent bonding which provides highly polarizable bonds with a strong lattice anharmonicity while maintaining the superior electrical conductivity. The electronic band structure exhibits nearly degenerate valence‐band maxima that help to achieve a high Seebeck coefficient throughout the measured temperature range and, as a result, the maximum thermoelectric figure of merit reaches to ≈1.2 at 661 K in pristine single crystal of AgSnSbTe3. [ABSTRACT FROM AUTHOR]

Comprehension of chemical bonding and its intertwined relation with charge carriers and heat propagation through a crystal lattice is imperative to design compounds for thermoelectric energy conversion. Here, we report the synthesis of large single crystal of new p‐type cubic AgSnSbTe3 which shows an innately ultra‐low lattice thermal conductivity (κlat) of 0.47–0.27 Wm−1 K−1 and a high electrical conductivity (1238 – 800 S cm−1) in the temperature range 294–723 K. We investigated the origin of the low κlat by analysing the nature of the chemical bonding and its crystal structure. The interaction between Sn(5 s)/Ag(4d) and Te(5p) orbitals was found to generate antibonding states just below the Fermi level in the electronic band structure, resulting in a softening of the lattice in AgSnSbTe3. Furthermore, the compound exhibits metavalent bonding which provides highly polarizable bonds with a strong lattice anharmonicity while maintaining the superior electrical conductivity. The electronic band structure exhibits nearly degenerate valence‐band maxima that help to achieve a high Seebeck coefficient throughout the measured temperature range and, as a result, the maximum thermoelectric figure of merit reaches to ≈1.2 at 661 K in pristine single crystal of AgSnSbTe3. [ABSTRACT FROM AUTHOR]

Comprehension of chemical bonding and its intertwined relation with charge carriers and heat propagation through a crystal lattice is imperative to design compounds for thermoelectric energy conversion. Here, we report the synthesis of large single crystal of new p-type cubic AgSnSbTe 3 which shows an innately ultra-low lattice thermal conductivity (κ lat ) of 0.47-0.27 Wm -1  K -1 and a high electrical conductivity (1238 - 800 S cm -1 ) in the temperature range 294-723 K. We investigated the origin of the low κ lat by analysing the nature of the chemical bonding and its crystal structure. The interaction between Sn(5 s)/Ag(4d) and Te(5p) orbitals was found to generate antibonding states just below the Fermi level in the electronic band structure, resulting in a softening of the lattice in AgSnSbTe 3 . Furthermore, the compound exhibits metavalent bonding which provides highly polarizable bonds with a strong lattice anharmonicity while maintaining the superior electrical conductivity. The electronic band structure exhibits nearly degenerate valence-band maxima that help to achieve a high Seebeck coefficient throughout the measured temperature range and, as a result, the maximum thermoelectric figure of merit reaches to ≈1.2 at 661 K in pristine single crystal of AgSnSbTe 3 ., (© 2023 Wiley-VCH GmbH.)