Synchrotron-based far-infrared spectroscopy of nickel tungstate

Abstract

Monoclinic antiferromagnetic NiWO 4 was studied by far-infrared (30-600 cm

X-ray absorption near edge spectroscopy of thermochromic phase transition in CuMoO4

“…Molybdates and tungstates find a wide range of practical applications due to their ability to adopt different crystallographic structures, whose physical properties can be further modified by a chemical composition [1,2]. In particular, these materials are used as scintillators, down-conversion phosphors, white light-emitting diodes, laser host materials, catalysts, sensors and pigments [3][4][5][6][7][8][9][10][11][12].…”

Lattice and spin dynamics in a low-symmetry antiferromagnet NiWO4

“…In this paper, we report on the lattice and spin dynamics in single crystals of the nickel wolframite NiWO 4 studied by polarized Raman spectroscopy. Recent studies of NiWO 4 powders using the synchrotron radiation in the infrared (IR) [28] and visible [29] spectral range allowed to get some insights on polar IR-active phonons, as well as on electron excitation bands. However, no magnetic excitations were found, probably due to the use of the powder samples, or to some other experimental limitations of the technique.…”

Low-temperature radiation effects in wide gap materials

“…One review article and 13 regular research papers cover a broad class of wide gap materials, starting from model single alkali halide crystals, both pure and doped [1,3,9,11], widely used for different applications pure and doped CaF 2 and BaF 2 alkali-earth halides [1], rutilestructured SiO 2 and GeO 2 crystals and glasses [6] or CdI 2 layered crystals [12] to less studied tungstate NiWO 4 [2,4] and lastly, perovskites BaLiF 3 [1] and BaZrO 3 [13]. The comprehensive review of the relaxation of the electronic excitations and luminescence of rutile-structured SiO 2 and GeO2 crystals and their detailed comparison with α-quartz crystals and relevant glasses was given in paper [6].…”

“…Besides many conventional experimental methods, such as optical absorption, luminescence, magnetic resonance, etc. [1,6,[8][9][10]12,13], the opportunities of synchrotron radiation techniques are also demonstrated for NaCl crystals and NiWO4 tungstates using both VUV [2,3] and IR [4] light beams. The use of nuclear reactor for the creation of novel radiation-defect-induced jewellery colors of minerals, such as agate (SiO 2 ), topaz (Al 2 [SiO 4 ](F,OH) 2 ), beryl (Be 3 Al 2 Si6O 18 ) and prehnite (Ca 2 Al(AlSi 3 O 10 )(OH) 2 ) doped with different concentration of transition metal ions was review by Mironova-Ulmane et al [10].…”

“…Where necessary, the obtained results were supported by other experimental methods such as SEM, TEM and x-ray diffraction. Special attention was also paid to modern theoretical methods of the electronic band structure calculation [4,5]. A new quantum field approach for the description of highly-excited insulator materials was developed in paper [7].…”