Broadband dielectric behavior of MIL-100 metal-organic framework as a function of structural amorphization.

The performance of modern electronics is associated with the multi-layered interconnects, encouraging the development of a 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 framework (MOF) obtained using different synthesis techniques in both the radio (4-1.5 MHz) and infrared (1.2-150 THz) frequency regimes, which are important for the microelectronics, infrared optical sensors, and high-frequency telecommunications. The impact of amorphization on broadband dielectric response was established based on: (1) The comparison in the dielectric characteristics of a commercially available amorphous Basolite F300 versus a mechanochemically synthesized crystalline MIL-100 in the MHz region. (2) By tracking the frequency shifts in the vibrational modes of MIL-100 structure in the far-IR (phonons) and mid-IR regions. We showed that various parameters such as 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 {\deg}C) on the electric and dielectric response in the MHz region, crucial for all electronic devices.