Quasi-static NMR spectra in paraelectric KH₂PO₄ and KU₂AsO₄

NMR spectra of 75As and 39K have been measured in unannealed and annealed crystals of KH2PO4 and KH2AsO4 in the paraelectric phase. The As paraelectric A spectrum disappears, while the B-spectrum intensity increases substantially upon approaching Tc. The K satellite linewidth shows characteristic minima at ±8° from a+45° where the lines in the ferroelectric phase cross. Together with spin-echo data, this is evidence of quasistatic inhomogeneous broadening. © 1984, Taylor & Francis Group, LLC. All rights reserved.