Ferroelectric films of deuterated glycine phosphite grown in a nitrogen atmosphere

Thin ferroelectric films of deuterated glycine phosphite are grown by evaporation in a nitrogen atmosphere on NdGaO$_3$ and $\alpha$-Al$_2$O$_3$ substrates. The strong- and small-signal dielectric response of the resulting structures is studied using an interdigitated electrode system predeposited on the substrate. Crystallization of the films in a nitrogen atmosphere makes it possible to significantly (up to 291 K) increase the temperature of the occurrence of dielectric hysteresis loops, which characterize the transition of the film in the ferroelectric state. Unlike films grown in a normal atmosphere, the small-signal dielectric anomaly is heavily smeared with respect to temperature, which is attributed to an inhomogeneous distribution of deuterium over the film.