Dielectric and AC Conduction Properties of Thermally Evaporated Lithium Niobate Thin Films

Abstract

Thin films of LiNbO3 are prepared by thermal evaporation onto well cleaned glass substrates at 2.66 x 10−3 Pa. The thicknesses of the dielectric films are measured by Tolansky technique (Fizeau fringes). The X‐ray diffractogram shows that the as deposited films are amorphous in nature. Aging and annealing effects are found to improve the dielectric properties. The capacitance and dielectric loss are measured from 303 to 463 K in the frequency range 1 to 30 kHz. The dielectric constant of a film of 80 nm thickness is found to be 8.01 at room temperature in the frequency range studied. From the ac conduction studies it is confirmed that the mechanism responsible for the conduction process in these films is electronic hopping. The intrinsic temperature coefficient of capacitance is estimated to 1500 ppm/K. Two activation energies are observed for the thermally activated process and the results are discussed.

Electrical properties of thermally evaporated tellurium thin films

“…Variations of e' and tan fi with frequency at different temperatures.value. Similar behaviour has been reported(Kannan et al 1990;Easwaran et al 1992) for Nd203 and LiNbO 3 thin films.…”

Electrical conductivity and interface phenomena in thin-film heterostructures based on lithium niobate and lithium tantalate

“…Taking into account that this study investigates films with a thickness of 200 nm and that most often the direct tunneling is only possible in films with thicknesses less than 2−3 nm and the Fowler-Nordheim tunneling is only possible in films with a thickness of an order of magnitude of several nanometers, these conduction mechanisms can be excluded from the consideration [12,13]. In [14,15] authors reported about the possibility to describe electric conductivity of lithium niobate films using the Ohm's law (at low fields), the Pool-Frenkel emission, the Schottky emission and the hopping conductivity.…”

Электропроводность И Интерфейсные Явления В Тонкопленочных Гетероструктурах На Основе Ниобата Лития И Танталата Лития

“…Учитывая то, что в настоящей работе исследуются пленки толщиной 200 nm, и то, что чаще всего прямое туннелирование возможно только в пленках, толщина которых составляет менее 2−3 nm, а туннелирование Фаулера-Нордгейма -в пленках с толщиной порядка нескольких нанометров, эти механизмы проводимости можно исключить из рассмотрения [12,13]. В литературе [14,15] сообщается о возможности описания электропроводности пленок ниобата лития с помощью закона Ома (в малых полях), эмиссии Пула-Френкеля, эмиссии Шоттки и прыжковой проводимости.…”