The Zeeman-split quadrupolar resonances of ${\mathrm{Ba}}^{137}$ and ${\mathrm{Ba}}^{135}$ in barium bromide dihydrate were observed by using coincident enhancement of proton magnetic resonance as a detector. It was found that $\frac{Q_{137}}{Q_{135}}$ is 1.543±0.003 and that the asymmetry parameter of the electric field gradient about the Ba site is 0.726±0.006.

• Received 18 December 1961

DOI:https://doi.org/10.1103/PhysRev.127.184