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Food insecurity affects nutrition, physical health and consequently one’s psychological well-being. Using a nationally representative longitudinal cohort of 29,308 Indian elderly people (aged 60+ years), this article examines the relationship between food insecurity and psychological distress. Self-reported emotional status experienced over the week before data collection was considered to construct psychological distress at the individual level. Based on the results of logistic regression, controlling for several demographic and socioeconomic factors, a strong relationship was observed between food insecurity and psychological distress among the Indian elderly. This relationship is moderately higher in females than in males when accounting for demographic and socioeconomic confounders. These findings have important policy implications urging intervention to enhance food security in the elderly at risk and to improve their physical and psychological health.

Oxide thin films attracted significant attention because of their favorable responses, especially dielectric and stable electrical properties. In this study, nanocrystalline (Mg0.95Zn0.05)TiO3 (MZT) films are deposited on Pt/TiO2/SiO2/Si and quartz substrates by radio-frequency (RF) reactive magnetron sputtering. The effect of deposition gas ratio, i.e., the proportion of oxygen and argon (O2/Ar) on broad band and microwave dielectric properties and impedance spectroscopy of MZT films are investigated. The dielectric properties showed a wide range of variation with the different O2/Ar ratios. The MZT film deposited in a pure oxygen environment showed the best dielectric properties, and the plasma survived which shows that the target is not fully oxidized. The impedance spectroscopy of the film deposited under a pure oxygen environment exhibited the single semi-circular arc. The Ag/ MZT/Pt thin films capacitors exhibited the best dielectric constant with low loss tangent. The microwave dielectric constant measured at different spot frequencies in the GHz range displayed inferior dielectric response as compared to their bulk counterparts. An equivalent circuit model to explain the Nyquist plots of MZT films are worked out. The observed electrical and dielectric characteristics of the thin films suggest interesting applications in dielectric mirror and integrated circuits.

In the present study the effect of Zn substitution on densification, microstructure, microwave and broad band dielectric properties of MgTiO3 ceramics were investigated. The (Mg1−x Zn x )TiO3 (x = 0.01–0.07) ceramics have been prepared by the conventional solid-state reaction method. The sintering conditions were optimized to obtain the best dielectric properties with maximum relative densities. The microwave dielectric properties are heavily influenced by the amount of x concentration. The optimum dielectric properties of e r ~ 17.34, Q × f o ~ 274 THz, τ f ~ -40.3 ppm/oC is obtained for (Mg0.95Zn0.05)TiO3 ceramics sintered at 1275 °C. The broad band dielectric properties of (Mg0.95Zn0.05)TiO3 ceramics were measured in the frequency range of 1–100 MHz, and temperature range of 133–483 K. Interestingly, the broad band dielectric properties show relaxation behaviour with frequency. The higher temperature dielectric spectrum of (Mg0.95Zn0.05)TiO3 (MZT) ceramics displayed a distinct dispersion, which is shifting towards a lower frequency side. The observed dielectric relaxation behavior is analyzed using Cole–Cole plot. Furthermore, voltage dependent capacitance behavior at different frequencies is studied for the MZT sample, and it’s interesting to note that the capacitance is stable with the variation in voltage. The electrical conductivity study is carried out as a function of frequency and temperature for MZT sample and the activation energy is calculated by using Arrhenius equation, which is found to be 0.07 eV at 10 MHz. The obtained dielectric response of MZT ceramics are suitable for dielectric resonator and type-1 RF capacitor applications.

Recently, the worldwide telecommunication industry is developing towards slighter and lighter technology. Thin film technology has been playing an important role in the field of miniaturization of various microwave devices and integration of various optical devices. Scientists and researchers have been giving intensive and continuous effort in the development of thin films. The dielectric thin films with good optical properties are used in the integrated optical device as antireflection coating, dielectric mirror, etc. Fabrication of thin-film capacitors using high dielectric constant materials can provide higher charge storage densities when they exhibit lower dielectric loss. Ferroelectric, piezoelectric oxide thin films of low leakage current, low hysteresis, and high stability are used in sensor and tunable microwave device applications. In this chapter, the recent progress in the fabrication of oxide thin films and their applications in different fields are discussed.

Small size (25 nm) Li 2 B 4 O 7 nanoparticles doped with different concentrations of Cu, Ag and co-doped with Cu, Ag were prepared by solid state sintering at 700 °C. The crystalline phase and particle sizes analysis were carried out by XRD and TEM. FTIR study reveals the formation of vibrational bonds at 1600–1200 cm −1 , 1500–700 cm −1 , 950–870 cm −1 and 870–415 cm −1 . The kinetic parameters of the TL glow curves were evaluated using CGCD procedure in R-software. The CW-OSL decay curves were fitted with third order exponential decay curves and photoionization cross sections of each component were evaluated. The lifetime of the main TL dosimetric peak were also calculated to check the stability of the signal. Dose responses of the synthesized Li 2 B 4 O 7 nanoparticles for both the TL and CW-OSL were studied in the range of 0.02 mGy to50 Gy and found to be linear upto this range. Fading of the CW-OSL decay curves were also studied. The MDD of the synthesized samples were also calculated and observed to be 15 μGy.

The present study reports the temperature dependence of dielectric response of Ni doped MgTiO3 ceramics over a broad frequency range. (Mg1−x Ni x )TiO3 (x = 0.00–0.07) ceramics are prepared by a solid-state reaction process. The processing parameters are optimized to achieve maximum relative density. Among all the samples, (Mg0.95Ni0.05)TiO3 (MNTO) ceramics is exhibited the highest density with the best microstructure at 1300 °C. The optimum microwave dielectric properties (e r ~ 17.44, Q × f 0 ~ 181 THz) are displayed by the sample doped with x = 0.05 wt%. The detailed dielectric studies are performed on (Mg0.95Ni0.05)TiO3 composition in two different frequency ranges, 100 Hz–100 kHz at 298–358 K and 1–100 MHz at 133–503 K, respectively. A dielectric constant of 18.26 at 100 MHz is observed for (Mg0.95Ni0.05)TiO3 specimen at temperature 503 K. The frequency dependent conductivity is explained based on the basis of Jonscher power law. Further, the DC conductivity results obey the Arrhenius law, and the obtained activation energies are found to be 0.41 and 0.06 eV for (Mg0.95Ni0.05)TiO3 ceramics, measured at 100 MHz for high temperature (293–503 K) and cryogenic temperatures (133–293 K), respectively.

We report the effects of oxygen mixing percentage (OMP) and annealing temperature on surface morphology, optical, dielectric and electrical properties of (Mg0.95Ni0.05)TiO3 (MNT) thin films deposited onto amorphous SiO2 and platinized silicon (Pt/TiO2/SiO2/Si) substrates by radio frequency (RF) magnetron sputtering. The annealed films exhibited the highest refractive index, 2.05, at 600 nm with an optical bandgap value of 4.33 eV. The metal–insulator–metal (MIM) capacitors of the MNT thin films were fabricated under different OMPs and the dielectric properties were analyzed by using Maxwell–Wagner two-layer theory and Koop’s phenomenological theory. MNT films prepared under 50% OMP displayed the highest dielectric constant (11.21) and minimum loss tangent (0.0114) at 1 MHz. The impedance spectroscopy of the films deposited under 50% OMP has been studied. The Nyquist plots of MNT films revealed two semi-circular arcs and is explained on the basis of an equivalent circuit model. The frequency-dependent alternative current (AC) conductivity followed the Jonscher’s power law. The activation energies are calculated using the Arrhenius relationship. The hopping frequency of the charged species was calculated, and the correlation between AC and direct current (DC) conduction mechanisms established in accordance with the Barton–Nakajima–Namikawa (BNN) relationship.

Mg(Zr 0.05 Ti 0.95 )O 3 (MZT) thin films have been deposited onto amorphous SiO 2 and platinized silicon (Pt/TiO 2 /SiO 2 /Si) substrates by RF magnetron sputtering at different oxygen mixing percentages (OMP). The effect of OMP and post annealing temperature at 600 °C on crystal orientation, surface morphology, optical, electrical and dielectric properties of crystallined MZT films are investigated. A change of preferred orientation from (1 0 4) to (1 1 0) has been observed with increasing OMP from 0% to 100%. The preferred orientation growth has been explained on the basis of Lotgering model by calculating the orientation factor. The optical properties such as refractive index and bandgap were strongly influenced with O 2 content. It is also observed that the refractive index and packing density decreases with increasing OMP, leading to an enhancement in the optical bandgap from 4.19 to 4.52 eV. The dielectric constant and dielectric loss of the films ranged between 5.0–15.69 and 0.082–0.0135. The MZT thin films deposited at 100% OMP exhibited the high dielectric constant and low loss tangent. Further, the DC conductivity with frequency follows Jonscher law and the activation energy found to be 0.32 eV for MZT films deposited in pure oxygen atmosphere. Nyquist plots of MZT films revealed two semi circular arcs and are explained on the basis of equivalent circuit model. A series of two parallel RC combination in series fit with experimental data. The I – V characteristics reveals that the leakage current density decreases from 1.136 × 10 −8 to 4.69 × 10 −9 A/cm 2 for OMP, 0–100%, respectively for electric field strength of 200 kV/cm.

We report a systematic investigation on crystal structure, microstructure, and microwave dielectric properties of (Mg1−xCox)TiO3 (x = 0–0.07) ceramics prepared by semialkoxide precursor method. All the as-made samples exhibit an ilmenite structure with an incredible reduction in sintering temperature from 1350°C to 1200°C. Lattice parameter increases with increasing Co content due to the larger ionic radius of Co2+ as compared to Mg2+. The relative density, dielectric constant, and Q × f0 values increase with increasing Co up to 0.05 and decreases for x > 0.05. This is attributed to local lattice distortion, maximum relative density, and uniform grain growth. Q × f0 values were enhanced from 126 THz for x = 0 to a maximum value 170 THz for x = 0.05. A best combination of microwave dielectric properties (er ~ 17.03, Q × f0 ~ 170 THz @ 9.4 GHz and τf of −40 ppm/°C) was obtained for (Mg0.95Co0.05)TiO3 ceramic sintered at 1200°C for 3 h. The observed results reveal (Mg0.95Co0.05)TiO3 ceramic as one of the promising dielectric materials for low-loss and millimeter-microwave applications.

We report the structural, optical, and microwave dielectric characteristics of (Mg0.95Co0.05)TiO3 (MCT) thin films deposited onto amorphous SiO2 (a-SiO2) substrates by RF magnetron sputtering for the first time. The role of the oxygen mixing percentage (OMP) on the growth, morphology, optical, and microwave dielectric properties of MCT thin films has been investigated. The as-deposited MCT films were x-ray amorphous and crystallined after annealing at 700 °C for 1 h in air. A preferred orientation of grains along the (110) direction has been observed with increasing OMP. Such a textured growth is explained by calculating the orientation factors from the Lotgering model. The dispersion in a refractive index with wavelength has been explained using a single oscillator dispersion model. Both the refractive index and bandgap of the films increases on annealing. The annealed films exhibit refractive indices in the range of 1.88–2.08 at 600 nm with an optical bandgap value between 3.95–4.16 eV. The increase in the refractive index is attributed to the improvement in packing density and crystallinity, and decrease in the porosity ratio, whereas the increase in bandgap is due to the decrease in intermediary energy levels within the optical bandgap. (Mg0.95Co0.05)TiO3 thin films exhibited a progressive increase in the dielectric properties with OMP and a maximum dielectric constant of r = 17.3 and low loss (tanδ ~ 1.1 × 10−3) at a spot frequency of 10 GHz for the films deposited at 75% OMP, beyond which they decreased. The improvement in dielectric properties with an increase in OMP has been correlated to the preferred orientation growth, reduction in oxygen vacancies, and strain. The prepared MCT thin films are suitable candidates for anti-reflection coatings and complementary metal-oxide semiconductor (CMOS) applications.

We report the structural, dielectric and leakage current properties of Co doped MgTiO3 thin films deposited on platinized silicon (Pt/TiO2/SiO2/Si) substrates by RF magnetron sputtering. The role of oxygen mixing percentage (OMP) on the growth, morphology, electrical and dielectric properties of the thin films has been investigated. A preferred orientation of grains along (110) direction has been observed with increasing the OMP. Such evolution of the textured growth is explained on the basis of the orientation factor analysis followed the Lotgering model. (Mg1-xCox)TiO3 (x = 0.05) thin films exhibits a maximum relative dielectric permittivity of ɛr = 12.20 and low loss (tan δ ∼ 1.2 × 10−3) over a wide range of frequencies for 75% OMP. The role of electric field frequency (f) and OMP on the ac-conductivity of (Mg0.95Co0.05)TiO3 have been studied. A progressive increase in the activation energy (Ea) and relative permittivity ɛr values have been noticed up to 75% of OMP, beyond which the properties starts deteriorate. The I-V characteristics reveals that the leakage current density decreases from 9.93 × 10−9 to 1.14 × 10−9 A/cm2 for OMP 0% to 75%, respectively for an electric field strength of 250 kV/cm. Our experimental results reveal up to that OMP ≥ 50% the leakage current mechanism is driven by the ohmic conduction, below which it is dominated by the schottky emission.