Current Applied Physics最新文献

Here we propose an experimental method for determining the magnetic anisotropy field in ferromagnetic materials. Our method involves examining the small-angle variation of spontaneous magnetization by the external magnetic field and interpreting the experimental result within the framework of the Stoner-Wohlfarth model applicable to ferromagnetic materials. This method allows for the extrapolation of magnetic anisotropy fields, even when they surpass conventional measurement limits. As a result, a broad range of magnetic anisotropy fields can be ascertained using a single experimental setup. Our proposed method serves as a versatile tool for analyzing large magnetic anisotropy energy which is an important parameter for future spintronic devices.

Transition metal oxides (TMOs) are one of the most exciting classes of materials due to their emergent phenomena over the past few decades. In general, the emergent phenomena in TMOs are driven by the chemical state of the TMOs. Therefore, it is vital to understand the correlation between the chemical state and the physical properties of the TMOs. X-ray photoelectron spectroscopy (XPS) is the most widely used method for analyzing the chemical state of materials. However, when using XPS to investigate the chemical properties of TMOs, a lack of clear theoretical explanations for the interpretation, including discussions of oxygen vacancies, inaccurate XPS peak fitting, and inaccurate calibration, often leads to misinterpretation. In this review, we present a brief introduction to XPS, the peak fitting/deconvolution method for analyzing the chemical state of TMOs, and several case studies that use XPS to correlate the chemical state and the physical properties of TMOs.

Dynamic random-access memories (DRAMs) are used as core memories in current computing methods based on the Von Neumann architecture. The DRAM demand continuously increases because of the increased amount of data and need for artificial intelligence computing. DRAM consists of one transistor and one capacitor. Data are stored in the capacitor representing “0” and “1”. DRAM capacitors are composed of metal–insulator–metal thin films. In this review, we summarize experimental methods for development of high-k insulators and metal thin films for DRAM capacitors using the atomic layer deposition (ALD) process. Future research directions for the development of high-k and metal thin films and their ALD processes are addressed for next-generation DRAMs.

Silicide-based materials drive great potential in developing mid-temperature range thermoelectric generators (TEGs) applications. However, realizing the efficient and stable silicide materials is still a constraint for its real potential device applications. Chromium silicide will likely become p-type thermoelectric materials in this direction for thermoelectric power generation applications. However, high thermal conductivity values impede the figure-of-merit (zT). The present work adopts the chromium silicide, adding different weight percentages of well-known ZrCoSbSn compounds employing the compaction spark plasma sintering (SPS) technique. By adopting these combinations, the thermal conductivity is significantly reduced by enhanced scattering of heat-carrying phonons by multiple interfaces. Also, the maximum power factor value of ≃ 2.1 × 10⁻³ W/mK² is achieved by employing a CrSi₂ -ZrCoSbSn compound addition. The enhanced figure-of-merit value (zT) ≃ 0.26 is realized in the temperature at 623 K for the CrSi₂-5wt% ZrCoSbSn compound material.

Interface engineering plays a pivotal role in manipulating the electrical transport and conduction mechanism of a synaptic device. In this work, the impact of Ti as an interfacial layer is systematically investigated by inserting ∼5 nm thin film at both interfaces of a functional layer (TiO₂). Interestingly, it was observed that Ti layers significantly regulate the migration of oxygen ions/vacancies at the interfaces yielding an improved stability from 10 to 200 cycles, sustained over a longer period ∼8 × 10³ s. Forming free and gradual transition in conductance on positive bias region under a controlled compliance current ∼0.3–17 mA demonstrates the multilevel switching highlighting the typical synaptic behavior of memristor. The ohmic conduction and space charge-limited current mechanism was found across the various resistive states signifies the trapping/de-trapping. Besides, other key parameters of synaptic device such as paired pulse facilitation, depression, and short-term memory together with the excellent transmittance in the visible spectral range makes our device adequate for innovative transparent neuromorphic applications.

The elevated energy demand and crises have rooted the urge to develop advanced electrode materials that can overcome the energy dilemma present all over the globe. Metal-organic frameworks (MOFs) have emerged as promising electrode materials in recent times due to their better electrochemical properties. Herein the metal ligand synergy produced in MOFs is observed for the same metal center (Cu) with different ligands i.e., benzene-1,3,5-tricarboxylate (1,3,5-BTC) and benzene-1,2-dicarboxylate (1,2-BDC). The hybrid device of the best performing MOF (Cu-1,3,5-BTC//AC) reveals the energy and power density of 88.32 Wh kg⁻¹ and 680 W kg⁻¹, respectively. Even at the highest current density of 15 A/g, the device retained the E_s of 21.25 Wh kg⁻¹ and P_s of 12,750 W kg⁻¹. Furthermore, the semi-empirical approach was utilized for the evaluation of capacitive and diffusive contributions.

Tungsten doped indium oxide (In₂O₃: W, IWO) thin films have been attracting increasing attention due to their excellent optoelectronic properties. Here, a series of IWO thin films were prepared using direct current (DC) magnetron sputtering method, by varying the sputtering pressure. Analysis revealed that the IWO films prepared under sputtering pressure of 0.4 Pa exhibited excellent optoelectronic performance, with low square resistance, resistivity, high carrier concentration and mobility. The resulting semi-transparent perovskite solar cells (ST-PSCs), with IWO fabricated under 0.4 Pa, yield a PCE of 15.71 % for the large area modules of 100 cm² (active area 64.8 cm²).

Different dyes and drugs used in industries when released without any treatment in water bodies cause water pollution. There is a need of synthesizing cost-effective and efficient photocatalyst for their degradation. Herein, Ba and Nd co-doped bismuth ferrite BFO (Ba_0.5 Bi_0.5 Nd_0.5 Fe_1.5 O₃) and BFO@G (Ba_0.5 Bi_0.5 Nd_0.5 Fe_1.5 O₃/Gr_0.375) were successfully fabricated. X-ray Diffraction and Fourier Transform Infrared Spectroscopy were performed to confirm the synthesis of samples. Electrochemical measurements were carried out to further evaluate the characteristics of fabricated catalysts and R_ct values of 3.90 Ω and 2.06 Ω were observed for BFO and BFO@G. BFO@G showed 72.72 % degradation of CV and 80.26 % of PC. The composite material showed enhanced performance due to the integration of graphene which provide additional conductive pathways and reduces the rate of electron-hole pair recombination. This research contributes valuable insights into the development of efficient photocatalytic materials for environmental applications.