Three newly designed pyrochlore oxides, Eu₂Tm₂O₇ (Tm = Hf, Sn, Zr), are analyzed for their magnetic, optical and electronic properties using ab-initio calculations within the context of density functional theory (DFT). We can refer these compounds as direct bandgap materials because there is a very slight difference between the height of bands at the Γ- and M-point. It is observed that bandgap engineering can be performed by replacing Hf with Sn and Zr. It is observed from total density of states (TDOS) plots that shape and height of curves is not the same in spin up and spin down channels, showing significant magnetic moment in these compounds. It is evident from magnetic properties that a major portion of total magnetic moment ($m_{tot}$) comes from Eu-atoms. In all compounds, the magnetic moment of O, Hf, Sn and Zr atoms is negative, whereas the magnetic moment of Eu-atoms is positive, showing their antiparallel arrangement. In both spin channels, significant absorption of the incoming photons is also shown by these compounds in the ultraviolet (UV) region. We can conclude on the basis of $R\left(\omega \right)$ that these compounds can be utilized in applications such as anti-reflecting coatings. These compounds are potential candidates for photovoltaic applications, such as solar cells, due to efficient absorption of incoming photons in visible and UV regions.

In the present era of advanced technology, the surge for suitable multifunctional materials capable of operating above 300 °C has increased for the utilization of high-temperature piezoelectric devices. For this purpose, a pseudo-tetragonal phased CaBi₄Ti_3.98 (Nb_0.5Fe_0.5)_0.02O₁₅:xwt%MnO₂ (CBTNF:xMn), with x = 0–0.20, ceramic system has been engineered for the investigation of structural, ferroelectric, dielectric and high-temperature-dependent piezoelectric properties. XRD analysis confirms that low-content Mn-ion insertion at the lattice sites of CBTNF does not distort the pseudo-tetragonal phase lattice of CBTNF:xMn ceramics, but enhances the functional behavior of the ceramic system, specifically at x = 0.15 wt%Mn. Compared to pure CBT and CBTNF ceramics, CBTNF:0.15Mn has demonstrated a highly dense relative density (~96%), a saturated polarization (P_S) of 15.89 µC/cm², a storage energy density (W_ST) of ~1.82 J/cm³, an energy-conversion efficiency (ƞ) of ~51% and an upgraded piezoelectric behavior (d₃₃) of 27.1 pC/N at room temperature. Sharp temperature-dependent dielectric constant (ε_r) peaks display the solid ferroelectric behavior of the CBTNF:0.15Mn sample with a Curie temperature (T_C) of 766 °C. The thermally stable piezoelectric performance of the CBTNF:0.15Mn ceramic was observed at 600 °C, with just a 0.8% d₃₃ loss (25 pC/N). The achieved results signify that multi-valence Mn ions have effectively intercalated at the lattice sites of the pseudo-tetragonal phased CBTNF counterpart and enhanced the multifunctional properties of the ceramic system, proving it to be a durable contender for utilization in energy-storage applications and stable high-temperature piezoelectric applications.

In the area of flexible electronics, pressure sensors are a widely utilized variety of flexible electronics that are both indispensable and prevalent. The importance of pressure sensors in various fields is currently increasing, leading to the exploration of materials with unique structural and piezoelectric properties. Perovskite-based materials are ideal for use as flexible pressure sensors (FPSs) due to their flexibility, chemical composition, strain tolerance, high piezoelectric and piezoresistive properties, and potential integration with other technologies. This article presents a comprehensive study of perovskite-based materials used in FPSs and discusses their components, performance, and applications in detecting human movement, electronic skin, and wireless monitoring. This work also discusses challenges like material instability, durability, and toxicity, the limited widespread application due to environmental factors and toxicity concerns, and complex fabrication and future directions for perovskite-based FPSs, providing valuable insights for researchers in structural health monitoring, physical health monitoring, and industrial applications.