Highly transparent indium-free multilayers of TiO₂/Cu/TiO₂ were obtained by means of annealing. The effects of Cu thickness and annealing temperature on the electrical and optical properties were investigated. The critical thickness of Cu mid-layer with optimal electrical and optical properties was 10 nm, with the figure of merit reaching as high as 5 × 10⁻³ Ω⁻¹. Partial crystallization of the TiO₂ layer enhanced the electrical and optical properties upon annealing. Electrothermal experiments showed that temperatures of more than 100 °C can be reached at a heating rate of 2 °C/s without any damage to the multilayers. The experimental results indicate that reliable transparent TiO₂/Cu/TiO₂ multilayers can be used for electrothermal application.

A two-step treatment, first chemical etching then thermal treatment, is proposed to achieve an atomically flat and thermally stable TiO₂-terminated SrTiO₃ substrate. LaAlO₃ films were then grown on those TiO₂-terminated and as-received substrates. LaAlO₃ films on the TiO₂-terminated SrTiO₃ substrate maintained the layer-by-layer growth mode with a sharp interface, while films on the as-received substrates easily underwent reconstruction adverse to the sharp interface. Both LaAlO₃/SrTiO₃ interfaces displayed metallic conductive behavior, while the difference in magnetotransport properties indicated the difference in origin for interface conductivity. Large positive magnetoresistance implied that the LaAlO₃/as-received substrate interface was a 3D conductive interface dominated by oxygen vacancies. However, the annealed-LaAlO₃/treated-substrate interface preserved intrinsic quasi-2D interface magnetism as evidenced by large negative magnetoresistance.

In order to meet the application requirements for high-precision and low-noise accelerometers in micro-vibration measurement and navigation fields, this paper presents the design and testing of an ultra-high-capacitance resolution capacitive readout circuit with attofarad-level precision. First, a differential charge amplifier circuit is employed for the first stage of capacitance detection. To suppress noise interference in the circuit, a frequency-domain modulation technique is utilized to mitigate low-frequency noise. Subsequently, a differential subtraction circuit is implemented to reduce common-mode noise. Additionally, an improved filtering circuit is designed to suppress noise interference in the final stage. The test results indicate that the designed circuit operates at a carrier frequency of 1 MHz, achieving a capacitance resolution of up to 0.103 aF/H${\mathrm{z}}^{1/2}$ and a noise floor of 25.6 $\mathsf{\mu }$g/H${\mathrm{z}}^{1/2}$, thereby meeting the requirements for high-precision and low-noise capacitance detection in MEMS accelerometers.

A batch of Sn oxides was fabricated by pulse direct current reactive magnetron sputtering (pDC−RMS) using different Ar/O₂ flow ratios at 0.3 Pa; the influence of stoichiometry on the physical and electrochemical properties of the films was evaluated by the characterization of scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray reflection (XRR), X-ray photoelectron spectroscopy (XPS) and more. The results were as follows. First, the film surface transitioned from a particle morphology (roughness of 50.0 nm) to a smooth state (roughness of 3.7 nm) when Ar/O₂ flow ratios changed from 30/0 to 23/7; second, all SnO_x films were in an amorphous state, some samples deposited with low O₂ flow ratios (≤2 sccm) still included metallic Sn grains. Therefore, the stoichiometry of SnO_x calculated by XPS spectra increased linearly from SnO_0.0.08 to SnO_1.71 as the O₂ flow ratios increased, and the oxidation degree was further calibrated by the average valence method and SnO₂ standard material. Finally, the electrochemical performance was confirmed to be improved with the increase in oxidation degree (x) in SnO_x, and the SnO_1.71 film deposited with Ar/O₂ = 23/7 possessed the best cycle performance, reversible capacity of 396.1 mAh/g and a capacity retention ratio of 75.4% after 50 cycles at a constant current density of 44 μA/cm².

ZnO:Al films were prepared by magnetron sputtering at room temperature. During the growth process, H radicals produced by radio frequency power sources were in situ introduced into ZnO:Al films. By injecting H radicals, the content of Al in ZnO:Al films increased from 3.4 at. % to 6.1 at. %, which could be ascribed to the reaction between H radicals and ZnO as well as the resputtering of the Zn element. Surface morphologies of ZnO:Al films were tuned from smooth shape to sunflower seed-like. Furthermore, ZnO:Al films without injecting H radicals showed highly c-axis preferential orientation and then nearly became amorphous with the addition of H radicals, which corresponds to the results of Raman spectra. The grain boundary potentials decreased due to the removal of oxygen at grain boundaries and an amount of Vo was produced, which was proved by Raman and x-ray photoelectron spectroscopy results. The optimal resistivity of as-grown ZnO:Al films co-doped with H radicals was 1.5 × 10⁻³ Ω cm at an H₂ ratio of 2.3%. The variation of the carrier concentration for annealed ZnO:Al films at different H₂ ratios supported the existence of H interstitials and Vo. The optical bandgap varied from 3.44 eV to 3.71 eV with increasing H radicals.

We proved that the critical thickness for metal-to-insulator transition (MIT) of LaNiO₃ could be controlled by substrate orientation. By means of density functional theory calculations, films grown on SrTiO₃ substrates with (001), (110) and (111) orientations have different amount of charge transfer across the interface. Different charge transfer induces different interfacial conductivity behavior and at the same time modifies the carrier density of adjacent LaNiO₃ films. The manipulation of MIT by substrate orientation can be achieved through interfacial charge transfer induced interfacial conductive layer with the modified conductivity of LNO layer.