Fig. 4: Structural characterization.

Temperature-related dielectric constants and loss of a pristine BNT, b BNKLST, and c BNKLSTN5 ceramics; XRD patterns of d pristine BNT, e BNKLST, and f BNKLSTN5 ceramics; g Phase fraction by XRD refinements; h Temperature-related in situ XRD patterns of BNKLSTN5 ceramic; i Temperature dependence of the (111) peak and corresponding contour map; j Temperature dependence of the (200) peak and corresponding contour map; k Temperature-related in situ Raman spectra of BNKLSTN5 ceramic; The variations in wavenumber and FWHM of the peak at l 272 cm−1 and m 543 cm−1.