CHARACTERIZATION AND CAPACITIVE BEHAVIOR OF XENOTIME FROM THE ATOTONILCO EL GRANDE FORMATION, HIDALGO, MÉXICO.

Abstract

The capacitive behavior and structural characterization of xenotime located in the Atotonilco el Grande Formation, Hidalgo, Mexico, were investigated. The study area is associated with an extensional rift environment known as the Molango Rift, where tectonic and volcanic processes facilitated the concentration of strategic minerals such as xenotime.

Xenotime was characterized using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (SEM–EDS), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The identified crystalline phases include xenotime-(Y) (PDF 96-101-1144) and xenotime-(Yb) (PDF 96-152-9051). The xenotime particles exhibit subhedral morphologies, along with mineral phases such as zirconium pyrophosphate (ZrP₂O₇, PDF 96-153-4358) and pretulite (ScPO₄, PDF 96-900-1950), which may be remnants of diffusive metasomatic processes that promoted isomorphic substitution of rare earth elements within a phosphorus- and zirconium-rich matrix.

Electrical tests demonstrated that xenotime behaves as a high-pass filter (HPF), with efficient signal response above 100 kHz, suggesting its potential use in high-frequency electronic devices. Thermal characterization revealed high dielectric constants (~500) and two ferroelectric transitions (at 70 °C and 300 °C), indicative of a Class I dielectric material with Class II ferroelectric stability.

These findings position xenotime as a promising material for the technology sector, particularly in the development of high-stability capacitors, energy storage devices, and solid-state rectifiers. Furthermore, the study underscores the relevance of rift systems as favorable geological environments for the concentration of strategic critical elements in Mexico, encouraging new exploration strategies for high-tech mineral resources.