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

TL;DR

This study investigates how the transition from crystalline to amorphous states in MIL-100 metal-organic frameworks affects their broadband dielectric, optical, and electrical properties across various frequencies, relevant for electronics and sensors.

Contribution

It provides a comparative analysis of dielectric responses between crystalline and amorphous MOFs and explores the effects of synthesis methods and amorphization on their broadband properties.

Findings

Amorphization significantly alters dielectric properties.

Frequency shifts in vibrational modes indicate structural changes.

Temperature influences dielectric response in the MHz range.

Abstract

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.