Broadband characterization of congruent lithium
Auteurs
C. Charlotte, S. Thiemo, B. Naoufal, H. Alexei, and G. Torsten
Référence
Journal of Physics D: Applied Physics, vol. 50, no. 36, art. no. 36LT01, 2017
Description
Lithium niobate (LiNbO3) is a well known uniaxial ferroelectric material. Using impedance measurement, quasi-optical free-space characterization, THz time domain spectroscopy (THz–TDS) and ellipsometry, its dielectric permittivity/refractive index was characterized depending on the crystal orientation over a broad frequency range: 1 mHz to 1 PHz ($\lambda = 300$ nm). Three different frequency ranges, separated by well identified resonances, are observed: low frequency 'free-piezoelectric' response, intermediate frequency 'clamped-ionic' response and high frequency 'electronic' response. These features are discussed with an emphasis on the role of the crystallographic structure and piezoelectric response.
