High‑κ Samarium-Based Metal–Organic Framework for Gate Dielectric Applications

The self-assembly of a samarium-based metal–organic framework [Sm2(bhc)­(H2O)6]n (1) in good yield was achieved by reacting Sm­(NO3)3·6H2O with benzenehexacarboxylic acid (bhc) in a mixture of H2O–EtOH under hydrothermal conditions. A structural analysis showed that compound 1 crystallized in a space group of Pnmn and adopted a 3D structure with (4,8) connected nets. Temperature dependent dielectric measurements showed that compound 1 behaves as a high dielectric material with a high dielectric constant (κ = 45.1) at 5 kHz and 310 K, which is comparable to the values for some of the most commonly available dielectric inorganic metal oxides such as Sm2O3, Ta2O5, HfO2, and ZrO2. In addition, electrical measurements of 1 revealed an electrical conductivity of about 2.15 × 10–7 S/cm at a frequency of 5 kHz with a low leakage current (Ileakage = 8.13 × 10–12 Amm–2). Dielectric investigations of the Sm-based MOF provide an effective path for the development of high dielectric materials in the future.