Levy Shahar, Keren Amit
Department of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel.
J Magn Reson. 2004 Apr;167(2):317-21. doi: 10.1016/j.jmr.2004.01.005.
We present an angle dependent nuclear quadrupole resonance (ADNQR) method to determine the electric field gradient asymmetry parameter eta in systems where the resonance line is so broad that the radio frequency field can excite only a portion of the nuclear spins. In this situation, the recently developed spectroscopic methods are not applicable. ADNQR is useful for single crystals and oriented powders, and, for small eta determines eta4. Therefore, it can be used to evaluate fluctuations in eta due to inhomogeneities. We demonstrate the application of ADNQR experimentally to oriented superconducting YBa2Cu3O7 powder.
