We have studied the electronic and magnetic properties of BaTiO3 (BTO)/La0.7Sr0.3MnO3(LSMO) bilayer thin films deposited by pulse laser deposition on SrTiO3 (100) substrate. X-ray diffraction and reciprocal space mappings show that the grown bilayers are single phase and epitaxial in nature. We observed by the X-ray absorption study that the relative hybridization of t2g orbitals of Ti 3d with oxygen 2p decreases with increasing Ti3+ fraction in the BTO layer. We found the anomalies in magnetization versus temperature behaviour near the structure transition of BTO, indicating coupling of the LSMO layer with the BTO structure. We also observed the pinched M-H hysteresis loop at low 5 K in this bilayer, and this pinched behaviour completely disappeared when the BTO layer is used as the bottom layer of the bilayer. It is shown that this pinched hysteresis behaviour arises because of coupling of Ti3+ which is present at the interface in the nonstoichiometric BTO top layer with the bottom LSMO layer at the interface.

Metal organic frameworks (MOFs) are crystalline materials with ultrahigh porosity and tunable physico-chemical properties. But most MOFs are electrical insulators which restricts their use in electronic devices. In the present study, a field effect transistor (FET) based on a proton-conductive MOF was investigated. Imidazole was used as a proton conductor to increase the conductivity of the copper benzene tricarboxylate (CuBTC) MOF and, further, it was used to develop the FET. The CuBTC was synthesized using the traditional solvothermal method. The proton-conductive MOF was synthesized by post-modification of the CuBTC via the pore filling method using imidazole molecules, which achieved a proton conductivity of ~1.04 × 10 −4 S cm −1 at 70 °C (anhydrous conditions). The proton conductive MOF was characterized by various techniques; spectroscopically by Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, x-ray absorption spectroscopy, energy dispersive spectroscopy, alternating current (a.c.) impedance spectroscopy; thermally using thermogravimetric analysis; structurally using powder x-ray diffraction; morphologically using field emission scanning electron microscopy; electrically by FETs.

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Nitrogen‐containing carbons (NC) are a class of sustainable materials for selective CO2 adsorption. A versatile concept is introduced to fabricate flexible NC‐based sensor architectures for room‐temperature sensing of CO2 in a one‐step laser conversion of primary films cast from abundant precursors. By the unidirectional energy impact in conjunction with depth‐dependent attenuation of the laser beam, a layered sensor heterostructure with a porous transducer and active sensor layer is formed. Comprehensive microscopic and spectroscopic cross‐sectional analyses confirm the preservation of the high content of imidazolic nitrogen in the sensor. The performance is optimized in terms of material morphology, chemical composition, and surface chemistry to achieve a linear relative resistive response of up to ΔR/R0 = −14.3% (10% of CO2). Thermodynamic analysis yields ΔadsH values of −35.6 and 34.1 kJ·mol−1 for H2O and CO2, respectively. The sensor is operable even in humid environments (e.g., ∆R/R0,RH = 80% = 0.53%) and shows good performance upon strong mechanical deformation.

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We report the modifications in the electronic properties of single phase polycrystalline BaTiO3 due to ferroelectric to paraelectric phase transition revealed by temperature dependent synchrotron based x-ray absorption and valence band spectroscopy. Valence band spectra show a strong temperature dependence of Ti-3d and O-2p hybridized states around the phase transition. It is observed that Ti-O hybridization is stronger in the paraelectric phase, which is also supported by multiplet calculations at the Ti L-edge. We also find a reduced crystal field value in the paraelectric phase than in the ferroelectric phase, which is caused by volume expansion and a reduction in tetragonal distortion.

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