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

Abstract

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Ba-induced phase segregation and band gap reduction in mixed-halide inorganic perovskite solar cells

“…We were unable to detect any 137 Ba signal on the CsPb 0.8 Ba 0.2 Br 3 composition over 12 h using an RF strength of 125 kHz, which should be sufficient to detect such a narrow resonance (Supplementary Fig. 6), suggesting that the barium species present in the composition have very large EFGs, consistent with asymmetric non-perovskite barium environments 34 . Taken together, the 133 Cs and 137 Ba NMR results are compelling evidence for no barium incorporation into the CsPbBr 3 perovskite lattice.…”

New Methods and Applications in Solid-State NMR Spectroscopy of Quadrupolar Nuclei

“…Over 74% of the nuclides in the Periodic Table have spin quantum number I > 1/2, and for over 63% elements the only NMR-active isotopes are quadrupolar, meaning that there are no I = 1/2 counterparts available for study. However, quadrupolar nuclei, such as 2 H, 6/7 Li, 11 B, 14 N, 17 O, 23 Na, 25 Mg, 27 Al, 35 Cl, 39 K, 59 Co, 69/71 Ga and 93 Nb, are of importance across the fields of chemistry, physics, biology, materials science and geology, as they are present in inorganic oxides, functional materials and ceramics, glasses and clays, polymers, pharmaceuticals and biomaterials, energy materials and in the compounds that make up the inner layers of our own planet. 1,2,[14][15][16][17][18][19][20] The development of methods for studying these nuclei using NMR spectroscopy, and the ability to exploit the site-specific and atomic-scale structural information this provides is, therefore, crucial.…”

A multinuclear solid-state magnetic resonance and GIPAW DFT study of anhydrous calcium chloride and its hydrates

“…[4][5][6] These tensors are important SSNMR observables, and a number of recent studies have illustrated that magnetic shielding and EFG tensor calculations using GIPAW DFT can provide additional insights in the study of a variety of chemical systems. [7][8][9][10][11][12][13][14][15][16][17] There is an increasing interest in "NMR crystallography", which pertains to obtaining molecular-level and crystal structure information for solid materials using SSNMR data. 18 Although there have been a number of exciting recent advances in this area of research, 6,[19][20][21][22][23][24][25] one cannot currently convert SSNMR data into a unique solid-state structure in a completely generalized manner.…”