The domain structure of ferroelastic BiVO₄studied by magnetic resonances

Abstract

The domain structure of the fenoelastic BiVOa single crystal has been investigated using the nuclear magnetic resonance (NMR) of "V and by the electron panmagnetic resonance (WR) of the Mn2+ ions contained in the crystal as an impurity. The 14 resonance lines of "V ( I = f ) in a BiVOd cryswl with the twin domain were measured in the crystallographic U& (or c-b) and e-a (or 0 -c ) planes with an FT NMR spectrometer. Two sets of Mn2; EPR signals were also obtained in the C(I plane. These two Sets of NMR and EPR signals originate from the twin-domain StNCtUre. From these two sets of experimentd data from ''V NMR and MnZ+ EPR. it is confirmed that the BiV04 single crystal has the prominent (W-plane) domain wall reported previously. The investigated domain S t N C t U E is found to be stable with time in COntmSt with a previous report by Bamn el al. The previous model of the twinning mechanism derived fmm NMR and x-ray diffraction data has been improved by employing the FPR results. The observed W plane of the domain wall in BiVOa can be explained by the ferroelastic Species 4Immm F 2 / m instead of 41" F 2 / m .

Orientation of electric field gradient and chemical shift tensors in BiVO4 at room temperature by51V NMR

“…Subg Q sequent studies have conÐrmed these results. 5,6 In this paper, we present the analysis of static and magic angle spinning (MAS) powder spectra recorded at various static magnetic Ðelds and spinning rates and conÐrm the earlier literature data. Further, we determined the relative orientation of the principal axis system (PAS) of the chemical shift anisotropy (CSA) tensor with respect to that of the electric Ðeld gradient (EFG) tensor.…”

Ferroelastic Phase Transition of BiVO4 Single Crystals with Prominent W -Domain Walls by Stress-Strain Hysteresis Measurements

“…From our previous results obtained with NMR, EPR, X-ray diffraction and TEM technique the prominent W plane with an angle of 44.5 with respect to the [100] axis was reported (Moon et al, 1987;Lim et al, 1989Lim et al, , 1990Lim et al, , 1992Lim et al, , 1995Lim et al, , 1996Yeom et al, 1994;Yeom, 2003). The twin-domain crystal grown by our group has only prominent W domain walls and no non-prominent W 0 -domain walls.…”

Electron paramagnetic resonance characterization of Cr3+ impurities in a β-Ga2O3 single crystal

“…Since the EPR method is very sensitive to the domain structure, 21 the crystal used in this study had a single domain, although single ␤-Ga 2 O 3 crystals tend to grow as twins. Ga 2 O 3 and Cr 2 O 3 powder were mixed as the starting material, pressed into a cylinder in a static pressure chamber, and then sintered at 1350°C for 1 h. The furnace used had an ellipsoidal shape and was called a coupled ellipsoidal image furnace.…”