Hydrostatic pressure has negligible effect on the resistivity anomaly and thec_H/a_H ratio of Ti₂O₃. The results are consistent with the band-crossing mechanism wherein the a^T and e^T bands cross as thec_H/a_H ratio increases.

Lattice imaging technique of high resolution electron microscopy has been employed to examine 4H, 6H and 9R ABO₃ perovskite polytypes. The lattice images can be correlated with the lattice periodicity and the stacking sequence of AO₃ layers and BO₆ octahedra. The study shows the utility and validity of the lattice imaging technique for the study of relatively close-packed systems.

X-ray and ultraviolet photoelectron spectroscopy as well as x-ray absorption spectroscopy have been employed to investigate transition metal oxide perovskites of the general formula ABO₃ (A = La or rare-earth ion, B=trivalent transition metal ion). Systematics in the core levels and in the valence bands in the series of LaBO₃ compounds have been discussed. Lanthanum chemical shifts in the x-ray absorption spectra in this series show interesting trends. Photoelectron spectra of the solid solutions, LaNi_1−xCo_xO₃, LaNi_1−xFe_xO₃ and LaFe_1−xCo_xO₃ show that the rigid band model is applicable to these systems. It is shown that x-ray photoelectron spectroscopy can be employed to identify multiple oxidation states of transition metal ions in oxide perovskites.

L₃VV Auger transitions of copper alloys show a feature due to a band-like states, the shape and intensity of which depend on the composition. The energy separation between this feature and the L₃M_4·5M_4·5 peak increases progressively with Cu concentration.

An indigenous electron energy loss spectrometer has been designed and fabricated for the study of free molecules. The spectrometer enables the recording of low-resolution electronic spectra of molecules in the vapour phase with ready access to the vacuum ultraviolet region. Electron energy loss spectra of aliphatic alcohols and carbonyl compounds as well as of benzene derivatives have been recorded with the indigenous spectrometer and the electronic transitions in these molecules discussed.

Oxides of the Y-Ba-Cu-O system are found to show onset of superconductivity in the 100–120 K region.

The oxide responsible for high-temperature superconductivity (onset ∼100 K, zero resistance above liquid N₂ temperature) is found to be YBa₂Cu₃O₇±δ.

Superconductivity is found in tetragonal La_3−xBa_3+xCu₆O_14+δ and La, Ba)_6−xSr_xCu₆O_14+δ even though they do not possess Cu-O chains or the K₂NiF₄ structure. Resistivity measurements confirm the occurrence of a transformation from chain-superconductivity to sheet-superconductivity in YBa₂Cu₃O_7−δ as δ is varied in the range 0.0–0.5.

Some of the Bi-Ca-Sr-Cu-O compositions show indications of onset of superconductivity in the 200–300 K region, possibly due to the intergrowth of different layered sequences.

Likely presence of superconductivity in layered nickelates of K₂NiF₄ structure is pointed out.

Magnetoresistance (MR) in bulk samples of LaMnO₃ has been investigated by varying the Mn⁴⁺ content from 10 to 33 per cent by chemical means, without aliovalent doping. With the increase in Mn⁴⁺ content, the structure of LaMnO₃ changes first from orthorhombic to rhombohedral and then to cubic and the material becomes increasingly ferromagnetic, exhibiting a resistivity maximum akin to an insulator-metal transition atT_Peak, just below the ferromagneticT_c. The magnitude of MR is highest in the cubic sample (with 33% Mn⁴⁺) around theT_Peak, and negligible in the non-magnetic orthorhombic sample (12% Mn⁴⁺).