The reactions of C(3P) with H2, HC1, HBr, and CH30H(D) were investigated in a crossed-beam configuration using laser ablation of graphite as the source of C(3P). Upon pulsed irradation of graphite with focused laser output at 266 and 355 nm, hyperthermal C(3P) is produced and expands freely into the vacuum. In this "free ablation" mode, directional beams of monomeric carbon are produced with a peak velocity of -8000 m s-l and a broad velocity distribution that can be described by temperatures of -21 000 and -9500 K when using 266 and 355 nm ablation wavelengths, respectively. Using 266 nm ablation, the endothermic reactions of C(3P) with the title molecules were investigated by probing the CH product. CH is produced predominantly in v = 0 with rotational distributions that are well described by temperatures in the range 1500-2200 K, depending on the molecular reactants. The spin-orbit and A-doublet sublevels are equally populated. In reactions with CH30D, both CH and CD are detected, identifying both the methyl and the hydroxyl groups as reactive sites. Comparisons with the CH intemal energy distributions obtained in the reaction of C(lD) with H2 show remarkable similarities. On the basis of theoretical investigations and the known electronic states of the methylene intermediate, it is suggested that the reactions of both C(3P) and C('D) proceed via insertion involving carbene intermediates. The participation of several low-lying states of the carbenes may lead both to lowering of the activation barrier for insertion and to CH products with similar populations of the two A-doublet components.

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Two‐dimensional electron gas (2DEG) formed at the interface of perovskite oxides has drawn considerable interest due to its rich underlying physics and potential in future generation spin‐electronic devices. Electrostatic gating and light illumination are two frequently applied stimuli for such devices. In this work, electrical conductivity tuning of a recently discovered conducting interface of crystalline LaVO3 and KTaO3 (LVO−KTO) is reported through electrostatic gating as well as light illumination. Signature of significant photoconductivity as well as persistent photocurrent is observed. A giant enhancement of resistance is found to occur under light illumination when a negative electrostatic gate bias (VG > −8 V) is applied. These effects offer a possible control on carrier density of the oxide interface, which is otherwise difficult due to their huge intrinsic carrier density. Further, a protocol deploying light and gate bias in an appropriate sequence is demonstrated to use this interface as a possible optical‐switch or memory storage device.

Long after the heady days of high‐temperature superconductivity, the oxides came back into the limelight in 2004 with the discovery of the 2D electron gas (2DEG) in SrTiO3 (STO) and several heterostructures based on it. Not only do these materials exhibit interesting physics, but they have also opened up new vistas in oxide electronics and spintronics. However, much of the attention has recently shifted to KTaO3 (KTO), a material with all the “good” properties of STO (simple cubic structure, high mobility, etc.) but with the additional advantage of a much larger spin‐orbit coupling. In this state‐of‐the‐art review of the fascinating world of KTO, it is attempted to cover the remarkable progress made, particularly in the last five years. Certain unsolved issues are also indicated, while suggesting future research directions as well as potential applications. The range of physical phenomena associated with the 2DEG trapped at the interfaces of KTO‐based heterostructures include spin polarization, superconductivity, quantum oscillations in the magnetoresistance, spin‐polarized electron transport, persistent photocurrent, Rashba effect, topological Hall effect, and inverse Edelstein Effect. It is aimed to discuss, on a single platform, the various fabrication techniques, the exciting physical properties and future application possibilities of this family of materials.

Photoelectrochemical hydrogen evolution via the p-SiNWs–Ta2O5–NGQD heterostructure.