Broadband Dielectric Behavior of an MIL-100 Metal–Organic Framework as a Function of Structural Amorphization

The performance of modern electronics is associated with multi-layered interconnects, encouraging the development of low-k dielectrics. Herein, we studied the effects of phase transition from crystalline to amorphous on dielectric, optical, and electrical properties of MIL-100 (Fe) and Basolite F300 metal–organic frameworks obtained using different synthesis techniques in both the radio (4–1.5 MHz) and infrared (IR, 1.2–150 THz) frequency regimes, which are important for the microelectronics, IR optical sensors, and high-frequency telecommunications. The impact of amorphization on the broadband dielectric response was established based on the following: (1) by comparison of the dielectric characteristics of commercially available amorphous Basolite F300 versus mechanochemically synthesized crystalline MIL-100 (Fe) in the MHz region and (2) by tracking the frequency shifts in the vibrational modes of the MIL-100 structure in the far-IR (phonons) and mid-IR regions. We showed that various parameters such as the pelleting pressure, temperature, frequency, density, and degree of amorphization greatly affect the dielectric properties of the framework. We also investigated the influence of temperature (20–100 °C) on the electric and dielectric responses in the MHz region, which are crucial for all electronic devices.