Special Issue: “Physics and Mechanics of New Materials and Their Applications”

Solid-state physics, directed to the design, manufacture, research, and further application of advanced materials and composites, play one of the most important roles in the quick development of modern science, techniques, and technologies. Devices and technical solutions, based on a broad spectrum of promising materials, operating at various scale levels and deciding numerous scientific tasks, are very interesting for modern industry and everyday life. The existing problems of high loads; aggressive media; and extremal, chemical, physical, and mechanical conditions require continuous attention and solution. New scientific areas also develop directly on the base of solid-state physics, as well as their achievements and applications.

This Special Issue consists of nine papers, including promising results, presented at the 2018 International Conference on “Physics, Mechanics of New Materials and Their Applications” (PHENMA-2018), which has taken place in Busan (Korea), 9–11 August 2018 (https://phenma2018.wordpress.com/, accessed on 14 September 2022).

Liu et al. [1] inserted a graphene oxide (GO) layer, manufactured as a Cu/GO/SiO₂/Pt structure, which could be resistively switched in a vaporless environment. The X-ray photoelectron spectra depth profile of this structure showed that the GO film caused Cu ionization in a vaporless environment with migration of Cu ions in an electrical field to the Pt electrode. By this, Cu-conducting filaments were formed and fractured by various polarity voltages, and the resistance of the structure reversibly switched in a vaporless environment. A schematic model was proposed to explain the switching mechanisms in the atmosphere and a vaporless environment. Andryushin et al. [2] studied the characteristics of the crystalline and grain structures of the PCR-13 material (based on the lead zirconate titanate (PZT) system), which was sintered in various ways. The microfluorescence analysis of the ceramic surface showed that micro X-ray fluorescence spectrometry, together with mathematical statistics, stated even small changes in the chemical composition of the ceramic samples. The optimal conditions were selected, which ensured the homogeneity, high-density ceramic structure, and reproducibility of characteristics. Abubakarov et al. [3] discussed phase formation in barium niobate, strontium, and their solid solutions (SSs) in the variable thermodynamic background conditions. The grain structure and dielectric properties, including relaxation phenomena, were studied. It was established that in the SSs of (1 − x)BaNb₂O₆–xSrNb₂O₆ (where 0.0 ≤ x ≤ 1.0), the maximum absorption of the super-high-frequency energy of electromagnetic radiation occurred in the area associated with structural instabilities of different natures, due to breaking of chemical bonds at the structure rearrangement, accumulation, and ordering of vacancies and impurity phases. These processes increased the number of interphase boundaries and the corresponding growth rates of dielectric losses. Pavelko et al. [4] investigated the crystal structure and surface morphology of ceramics, as well as the dielectric and thermal properties of Bi_1−xEr_xFeO₃ (where x = 0.05 − 0.20, Δx = 0.05) magnetoelectric solid solutions. The changes in phase composition, microstructure, and electrical and dielectric properties at room temperature were established. It was stated that the addition of 20% of erbium, at a temperature of 365 K, reduced by an order of magnitude of reach-through conductivity in the samples, as compared to pure bismuth ferrite. Miroshnichenko et al. [5] reported the governing relationships for the electromagnetic field on the surface of the laser beam splitter of a laser interferometer. These expressions were intended for the numerical simulation of measuring the displacements of control object surfaces using a laser interferometer. The cases of perpendicular and parallel polarizations of the radiation source, as well as the most relevant particular cases of constructing optical circuits of the interferometer, were treated. Sujito et al. [6] developed an improved symbolic analysis procedure to enhance the analytic efficiency of the reported symbolic nodal analysis. In order to reduce the order of the system of equations, by performing symbolic analysis, two techniques were applied in the proposed method. The first one used voltage signal sources directly to perform symbolic analysis without replacing them with their nullor equivalences. The second one used the nullor grounded mirror and floating mirror elements to model the active devices that involved differential or multiple single-ended signals. Tuan et al. [7] introduced a simple sound signal diagnostic method to evaluate the anterior cruciate ligament (ACL) injury before and after reconstructive surgery. Dynamic time warping of sound signals was applied to evaluate the healthy and injured limbs before surgery with those after surgery via variance analysis and Z-test analysis. It was shown that the wavelet analysis of knee sound can be used to evaluate the recovery status after single ACL reconstruction surgery. In order to ameliorate the anterior knee pain or peripheral pain around the tibia, caused by patellar lateral subluxation, Lu et al. [8] evaluated the kick training effects of standing or sitting postures in strengthening the vastus medialis obliquus (VMO) on the quadriceps femoris muscle. As a result, it was demonstrated that the leg kicking achieved the objective of enhancing the strength of VMO on the quadriceps femoris muscle. Vu et al. [9] examined the effects of washing highly PCDD/F- contaminated (where PCDD is the poly-chlorinated dibenzo-p-dioxin) field soil with two natural solvents (sugarcane and pineapple wine) under an ambient temperature. It was found that sugarcane wine more effectively removed the contaminants than pineapple wine due to its higher alcohol and acid content. It was the first study to employ naturally made wines as soil washing solvents in treating highly PCDD/F-contaminated field soil.

While submissions for this Special Issue have closed, many ideas and methods in the field of solid-state physics, connected with the manufacture, research, and application of novel materials and composites, continue to be developed, directed to quickly changing techniques, technologies, and industries.