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.