First-principles density functional theory (DFT) is employed to study the electronic structure of oxygen and gallium vacancies in monoclinic bulk β-Ga₂O₃ crystals. Hybrid exchange–correlation functional B3LYP within the density functional theory and supercell approach were successfully used to simulate isolated point defects in β-Ga₂O₃. Based on the results of our calculations, we predict that an oxygen vacancy in β-Ga₂O₃ is a deep donor defect which cannot be an effective source of electrons and, thus, is not responsible for n-type conductivity in β-Ga₂O₃. On the other hand, all types of charge states of gallium vacancies are sufficiently deep acceptors with transition levels more than 1.5 eV above the valence band of the crystal. Due to high formation energy of above 10 eV, they cannot be considered as a source of p-type conductivity in β-Ga₂O₃.

FinEstBeAMS (Finnish–Estonian Beamline for Atmospheric and Materials Sciences) is a multidisciplinary beamline constructed at the 1.5 GeV storage ring of the MAX IV synchrotron facility in Lund, Sweden. The beamline covers an extremely wide photon energy range, 4.5–1300 eV, by utilizing a single elliptically polarizing undulator as a radiation source and a single grazing-incidence plane grating monochromator to disperse the radiation. At photon energies below 70 eV the beamline operation relies on the use of optical and thin-film filters to remove higher-order components from the monochromated radiation. This paper discusses the performance of the beamline, examining such characteristics as the quality of the gratings, photon energy calibration, photon energy resolution, available photon flux, polarization quality and focal spot size.

Nanopowders of LaPO₄ have been grown by sedimentation-micellar method. As-prepared LaPO₄ nanoparticles with the average grain size of about 8 nm have a single-phase hydrated hexagonal structure. After thermal annealing at 600 and 800 °C, the average size of nanoparticles increases up to ∼35 and ∼50 nm, respectively, and the structure transforms into single-phase monoclinic. IR spectra of LaPO₄ nanoparticles of different size were investigated in the wide range of wavenumbers from 130 to 5000 cm⁻¹ in the 20–300 K temperature region. Differences between IR spectra of the bulk material and nanoparticles as well as the temperature behavior of the vibrational properties are discussed.