The aim of this research is to investigate the phase composition and structural peculiarities of complex metamorphic manganese ores from Central Kazakhstan before and after sintering in the temperature range of 600–1200 °C in an air atmosphere. X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and optical microscopy were used to analyze changes in elemental and phase composition. In their initial state, according to XRF analysis, the Bogach ore was manganese-rich, with a manganese content of 60.77 wt.%, while the Zhaksy ore contained manganese (44.88 wt.%), silicon (20.85 wt.%), and iron (6.14 wt.%) as its main components. In the Bogach ore samples, manganese content increased from 60.77% to 65.7% as the sintering temperature rose to 1100 °C, while the hausmannite phase (Mn₃O₄) emerged as the dominant phase, comprising 95.77% of the crystalline component at 1200 °C. Conversely, the Zhaksy ore samples displayed a sharp increase in braunite-phase (Mn₇O₁₂Si) content, reaching 83.81% at 1100 °C, alongside significant quartz amorphization. The degree of crystallinity in Bogach ore peaked at 56.2% at 900 °C but declined at higher temperatures due to amorphous phase formation. A surface morphology analysis revealed the transformation of dense, non-uniform particles into porous, granular structures with pronounced recrystallization as the temperature increased. In the Bogach samples, sintering at 900 °C resulted in elongated, needle-like crystalline formations, while at 1200 °C, tetragonal crystals of hausmannite dominated, indicating significant grain growth and recrystallization. For Zhaksy samples, sintering at 1100 °C led to a porous morphology with interconnected grains and microvoids, reflecting enhanced braunite crystallization and quartz amorphization. These findings provide quantitative insights into optimizing manganese oxide phases for industrial applications, such as catalysts and pigments, and emphasize the impact of thermal treatment on phase stability and structural properties. This research contributes to the development of efficient processing technologies for medium-grade manganese ores, aligning with Kazakhstan’s strategic goals in sustainable resource utilization.

ZIF-8 monoliths, and their Co-, Ni- and Cu-doped variants, are not suitable for water pollutant adsorption due to two key limitations: poor aqueous stability and restricted accessibility of large pollutants to the pores.

The vortex dynamics of an undoped uniaxially textured YBa₂Cu₃O_7−δ (YBCO) superconducting film grown onto a MgO (100) substrate was inspected by applying the vortex glass and collective-pinning models. The texture and structural characterization studied by X-ray diffraction revealed a uniaxially (00 l) YBCO layer, which coexists with minor Y₂BaCuO₅ and CuO phases. The temperature dependence of the magnetization in the superconducting state revealed a critical temperature T C = 88 K. By measuring the hysteresis loops ( M ( H ) ) at 10–70 K, the critical fields H C 1 , H C 2 , H P and H irr were estimated and a vortex matter diagram was sketched. By using the Bean model, the critical current density values J C ( T , H ) were obtained and the typical peak effect is observed. The vortex dynamics mechanism is discussed taking into account four vortex feature regimes in the double-logarithmical J C ( H ) curves. The vortex pinning mechanism is discussed by obtaining the pining force, F P , its normalization, f ( h ) , and magnetic relaxation M ( t ) measurements taken in field cooling mode at 10–60 K. The glassy exponent μ and the characteristic energy U ( J , T ) in the vortex glass model were estimated following the Maley method. The collective-pinning model is used to discuss the possible vortex regimes mechanism (individual flux lines, small bundles and large bundles of pinned flux). Eventually, the E ( J ) curves, expressed from the swept field and creep measurements, show a power-law behaviour, in agreement with the vortex matter.

We analyze in-plane and out-of-plane texture and terahertz analysis of a YBa₂Cu₃O_7-δ (YBCO) film deposited by chemical solution deposition technique onto LaAlO₃ (100) substrate. X-ray diffraction reveals the presence of (00l) reflections for the YBCO phase. The out-of-plane texture, measured by a rocking curve, shows two sub-layers with Δω = 0.45° and 1.8°. The value of the c-axis fraction of the crystallites is 81%. Also, the in-plane texture was studied by ϕ–scan measurements of (102) reflection, displaying mostly a colony of c-axis oriented grains, and two colonies of a-axis oriented grains onto the YBCO surface. In addition, the temperature dependence of the magnetization measurement revealed a critical temperature of 90 K, typical for YBCO superconductor material. From the temperature-dependent optical conductivity of YBCO, we observe an absorption feature at ≈1.57 THz, which redshifts with increasing temperature.

Experimentally obtained magnetic signals for a Fe–O nanocrystalline press compact were fitted using a phenomenological approach. This method considers the individual properties of microvolumes and their statistics. It also helps avoiding complex calculations while focusing on local fundamental magnetic characteristics without considering internal processes. Currently, the precise estimation of internal processes in local areas is nearly impossible. They depend on fluctuations in the anisotropy field, texture degree, and phase ratio. A cubic compact ( $10^{3}$ mm3 volume) was fabricated by pressing magnetite particles mixed with 20% iron by weight in a high-energy milling machine. After characterizing the compacts by X-ray diffraction (XRD), their magnetic signals were measured to obtain the saturation magnetization ( $M_{\text {s}} =0.97$ T), residual magnetization ( $M_{\text {r}} =0.456$ T), and coercivity ( $H_{\text {c}} =0.685$ kOe). The results suggest that the particle anisotropy fields relate to the effective anisotropy constants from the interaction between iron and magnetite particles. It is also found that single domains formed by iron particles contribute to high coercive states. This confirms that increasing the degree of texture results in an increment of the relative remanence and coercivity.