Phase transition and relaxation processes by 87Rb and 39K nuclear magnetic measurements of RbKSO4 single crystals

► 87Rb central line has the angular dependences of second-order quadrupolar shifts. ► The quadrupole coupling constant and the asymmetry parameter were determined. ► The spin-lattice relaxation rate, 1/T1, for the 87Rb and 39K nuclei. ► Raman processes with n=2 for the 87Rb and 39K nuclei.