Barium-137 nuclear magnetic resonance study in the various phases of

Abstract

quadrupole perturbed NMR measurements on a multidomain crystal were performed in order to determine the quadrupole tensors (which are proportional to the electric field gradient (EFG) tensors) in the tetragonal, orthorhombic and rhombohedral phase of . Because of the relatively large quadrupole splitting, only the central transitions were analysed. By means of the well known Volkoff theory the principal values and the directions of the principal axes were evaluated from the angular dependent NMR spectra. Furthermore, the correct determination of the principal values of the quadrupole tensors has been controlled by means of measurements on polycrystalline samples of the same origin. The conclusions from the measurements on the multidomain crystals are in very good agreement with the results of NMR line shape measurements on powdered samples. Moreover, the NMR studies on the crystal sample allow a study of the domain structure in the different ferroelectric phases in complete agreement with the predictions from symmetry considerations.

Solid-State 137Ba NMR Spectroscopy: An Experimental and Theoretical Investigation of 137Ba Electric Field Gradient Tensors and Their Relation to Structure and Symmetry

“…137 Ba SSNMR experiments could increase our understanding of the numerous barium-containing systems important in different applications such as glass manufacturing, well-drilling fluids, emulsification of liquids, NO storage, and the development of ultrasonic and electronic devices. − Notably, 137 Ba SSNMR may be especially valuable for characterization of materials for which crystal structures are unavailable or unobtainable (i.e., disordered solids, submicrocrystalline powders, etc.). However, of the relatively few 137 Ba SSNMR studies reported to date, most have focused on systems in which the barium sites exist in spherically symmetric environments, such as in BaO, BaTiO 3 , − BaZrO 3 , YBa 2 Cu 3 O y , , and Ba x Sr 1−x TiO 3 (0 ≤ x ≤1), which have small quadrupolar interactions and correspondingly narrow patterns. − MacKenzie et al reported the 137 Ba NMR spectra of several barium-containing systems acquired under conditions of magic-angle spinning (MAS), which were challenging to acquire due to the wide powder pattern breadths.…”

“…ferent applications such as glass manufacturing, well-drilling fluids, emulsification of liquids, NO storage, and the development of ultrasonic and electronic devices. [21][22][23][24] Notably, 137 Ba SSNMR may be especially valuable for characterization of materials for which crystal structures are unavailable or unobtainable (i.e., disordered solids, submicrocrystalline powders, etc.). However, of the relatively few 137 Ba SSNMR studies reported to date, most have focused on systems in which the barium sites exist in spherically symmetric environments, such as in BaO, 25 BaTiO 3 , [25][26][27][28] BaZrO 3 , 25 YBa 2 Cu 3 O y , 29,30 and Ba x Sr 1-x TiO 3 (0 e x e1), 31 which have small quadrupolar interactions and correspondingly narrow patterns.…”

“…[21][22][23][24] 3 (0 e x e1), 31 which have small quadrupolar interactions and correspondingly narrow patterns. [25][26][27] MacKenzie et al reported the 137 Ba NMR spectra of several barium-containing systems acquired under conditions of magicangle spinning (MAS), 32 which were challenging to acquire due to the wide powder pattern breadths.…”

35Cl Nuclear Magnetic Resonance Study in Bis(4-Chlorophenyl)Sulphone [(ClC6H4)2SO2]

“…[26]. A quadrupole echo pulse sequence with p/2 pulse length of 3 ms (and with phase cycling) was applied in order to circumvent problems with the dead time.…”

Combined 135/137Ba Solid-State NMR at an Ultrahigh Magnetic Field and Computational Study of β-Barium Borate

“…These unfavorable NMR characteristics make the observation of 135/137 Ba spectra difficult. As a result, 135/137 Ba solid-state NMR has only been applied to a limited number of materials such as BaO, BaMO 3 (M = Zr and Ti), − and YBa 2 Cu 3 O y , as well as some inorganic compounds and ceramic materials, namely BaCO 3 , BaFX (X = Cl and Br), and Ba x Sr 1− x TiO 3 . The vast majority of the Ba SSNMR studies were performed on 137 Ba because compared to 135 Ba, it has a higher Larmor frequency and a larger natural abundance despite of its larger quadrupole moment.…”