STRESS EFFECT ON 14N NQR IN THE FERROELECTRIC POLYCRYSTALLINE NANO2

The stress effect on 14N NQR in polycrystalline NaNO2 powder has been investigated in two ways: NQR measurements with the samples after the application of external stress and the measurements with the sample under the stress. For the powder samples which had been pressed, two extra v2± lines were observed in addition to the two normal v1± lines, and the stress dependence of these four lines is found to be different from each other. For the sample under the stress, the v+ frequency slightly decreases with the applied stress, whereas the frequency shift of the v− line was hardly appreciable up to 13 MPa. Both of the linewidths (Δv± and Δv−) increase with the applied stress. It is concluded that there exists a metastable state in the ferroelectric NaNO2, and a strain deformation, being elastic or plastic, is induced by applying the external stress to the NaNO2 powder. © 1990, Taylor & Francis Group, LLC. All rights reserved.