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This paper investigates the impact of high-energy sources, namely, high-energy plasma pulses and high-energy electron beam pulses, on materials in the form of layer through separate and combined exposures. Experimental setups utilizing a Rod Plasma Injector (RPI) and an electron gun were employed for irradiation tests. The studies involved pre- and post-treatment analysis of morphology, chemical, and phase composition using scanning electron microscopy and x-ray diffraction measurements. Surface modifications under different exposure conditions were characterized, revealing that both sources induced significant alterations in surface composition and crystal structure. These interactions result in a more uniform chemical composition, reduced surface roughness, and a shift from an amorphous phase to a nanocrystalline or amorphous-nanocrystalline state. The results underscore the potential of high-energy sources for efficient surface engineering, offering opportunities for customized material surface modifications through meticulous adjustment of these generation parameters. [ABSTRACT FROM AUTHOR]

The evolution of the structural and transport properties of underdoped La 1.952 Sr 0.048 CuO 4 thin films under a compressive epitaxial strain has been studied. The films of different thicknesses d (from 26 nm to 120 nm) were deposited using an insulating target. The onset of superconductivity in the films is observed at temperatures as high as 26 K, while small residual resistance persists at low temperatures, indicating that superconductivity is inhomogeneous. The resistance measured under a perpendicular magnetic field saturates below about 0.65 K, suggesting a possible existence of nonconventional metallic state. The magnetic-field-tuned quasi-superconductor to insulator transition is observed at a magnetic field of about 32 T. [ABSTRACT FROM AUTHOR]

The oxide glass–ceramics is a promising class of solid state materials because they are using thermally stable and chemically inert glass oxide matrices. Development of such efficient glass matrices suitable for creation of glass–ceramic materials for several purposes is an important practical task. The xLi2O–yV2O5–(100 − x − y)B2O3 undoped glass and 47Li2O–2V2O5–50B2O3–1La0.3Eu0.7VO4 glass samples with crystalline nanoinclusions were synthesized and investigated using XRD, IR and UV–Vis spectroscopy and UV band-to-band excitation of luminescence. The synthesized glass samples are characterized by wide band photoluminescence emission with maximum at 570 nm and intensity increased with increase of Li2O concentration. The excitation spectra consist of three bands with maxima located at 270, 320 and 365 nm. The observed concentration dependencies of spectral distributions in the absorption and excitation spectra are explained by influence of the lithium ions on a ratio between triborate and tetraborate groups in the glass networks. The assumption is made that the observed wide band photoluminescence emission of the glass matrix can appear as a result of recombination processes between the defects in borate networks and the broken vanadate groups. The crystalline component in the doped glass samples is found to not affect the luminescence properties of the glass matrix. Intensity of narrow band photoluminescence emission of the crystalline component is up to 10 times more intense than that of the glass matrix wide band emission. The synthesized type of the glass matrices has promising characteristics for the use of developed materials in lighting devices, as it allows improving the spectral distribution of light emission towards the white light. [ABSTRACT FROM AUTHOR]

The magnetocaloric effect has been studied in high quality single crystals of Fe7Se8 (3c type) grown by using Bridgman's method. Magnetization and magnetocaloric effect measurements have been carried out in a magnetic field up to 5 T over the temperature range from 2 to 490 K. The spin reorientation transition from the easy c-axis to the easy c-plane, proceeding in an abrupt fashion, as a first-order phase transition, has been observed near the temperature TR ≈ 125 K. The magnetization curves in the vicinity of this transition were shown to have an S-shape with a clear hysteresis. The first order metamagnetic field induced transitions have been identified above and below TR. The conventional magnetocaloric effect related to the metamagnetic transitions has been found above TR, while below TR the inverse magnetocaloric effect was clearly seen. The existence of both kinds of magnetocaloric effect is important from the point of view of large rotating field entropy change in Fe7Se8 single crystals. The refrigeration capacity associated with a second order phase transition from the ferrimagnetic to the paramagnetic state at the Néel temperature TN ≈ 450 K was found to be weaker than that appearing near TR. The giant anisotropy of the magnetocaloric effect was related to the magnetic anisotropy of Fe7Se8 crystals. The one-ion model of the magnetocaloric effect has been developed and its predictions have been compared with experimental data. [ABSTRACT FROM AUTHOR]

This article investigated the structural, transport, and magnetic properties of a series of samples in which the La(sub 0.67)Sr(sub 0.33)MnO3 (LSMO) layer thickness is fixed at eight unit cells and that of YBa2Cu3O7(YCBO) varied from one to six cells. Magnetic moment measurements present a qualitative agreement with the model.

New data on the state of Tb3+ doping ions in the EuAl3(BO3)4 single crystals have been obtained by studying the electron paramagnetic resonance spectra within the X band and optical absorption spectra at 4 K in the visible range. Additionally, the specific heat of these crystals was measured and analyzed. It has been shown that the Tb3+ ions substitute the trivalent europium ones and lower crystal symmetry. In the crystal field, the ground multiplet of Tb3+ splits in such a way that two singlets located in close proximity are the lowest energy levels. It has been shown that the temperature dependence of the linewidth can be described by the exponential function, which is characteristic of the Aminov-Orbach processes. [ABSTRACT FROM AUTHOR]

We present the studies of magnetic and electrical properties of Sn1-x-ySixMnyTe mixed crystals. The magnetic susceptibility measurements revealed the presence of two types of transitions interpreted as a paramagnet-ferromagnet transition at T < 10 K due to carrier mediated Ruderman-Kittel-Kasuya-Yosida magnetic interactions and the anomaly related to the structural transition to the rhombohedral phase at T = 75 K. The presence of a well-defined magnetic hysteresis with a square shape confirms that the ferromagnetic state present in our samples is related to the homogeneous magnetic domain structure with narrow domain energy distribution. The contents of the magnetic ions determined via magnetometric methods is lower than the Mn contents determined via the energy dispersive X-ray fluorescence spectroscopy method indicating the presence of a large fraction of Mn ions being either short range coupled into small clusters like pairs, triples, or other entities or having lower total magnetic momentum than Mn in high-spin state. The magnetic exchange constant of our samples is equal to 0.25-0.3 eV indicating an increase with respect to ternary Sn1-xMnxTe. [ABSTRACT FROM AUTHOR]

Ferromagnetic resonance (FMR) study of magnetic anisotropy is presented for thin layers of IV-VI diluted magnetic semiconductor Ge1-xMnxTe with x=0.14 grown by molecular beam epitaxy on KCl (001) substrate with a thin PbTe buffer. Analysis of the angular dependence of the FMR resonant field reveals that an easy magnetization axis is located near to the normal to the layer plane and is controlled by two crystal distortions present in these rhombohedral Ge1-xMnxTe layers: the ferroelectric distortion with the relative shift of cation and anion sub-lattices along the [111] crystal direction and the biaxial in-plane, compressive strain due to thermal mismatch. [ABSTRACT FROM AUTHOR]