Temperature dependent nanoscale atomic correlations in Ir1-xPtxTe2 (x = 0.0, 0.03 and 0.04) system

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid State Chemistry

Background:

• Iridium telluride (IrTe2) exhibits a first-order structural phase transition from trigonal to monoclinic.
• Platinum substitution in IrTe2 can lead to superconductivity.
• Understanding the electronic and structural properties is crucial for material applications.

Purpose of the Study:

• Investigate the unoccupied electronic states and local geometry of Ir1-xPtxTe2 (x = 0.0, 0.03, 0.04) using XANES.
• Analyze the impact of temperature and Pt substitution on structural and electronic properties.
• Elucidate the role of atomic correlations in the observed phenomena.

Main Methods:

• X-ray absorption near-edge structure (XANES) spectroscopy at the Ir L3-edge.
• Temperature-dependent measurements to probe phase transitions.
• Analysis of spectral weight transfer and high energy features.

Main Results:

• Pt substitution alters unoccupied 5d-electronic states and local geometry.
• Anomalous spectral weight transfer observed in IrTe2 at the trigonal-monoclinic transition.
• Pt-substituted samples (superconductors) show no temperature-induced spectral changes.
• Further decrease in symmetry suggested for IrTe2 below the transition temperature.

Conclusions:

• The interplay between inter-layer and intra-layer atomic correlations significantly influences Ir1-xPtxTe2 properties.
• Pt substitution modifies the electronic structure and suppresses phase transition anomalies.
• XANES is effective in characterizing electronic and structural changes in transition metal dichalcogenides.