Doping and Temperature Dependence of Raman Scattering of NdFeAsO1-xFx (x=0.0, 0.1, 0.2) Superconductor

TL;DR

This study investigates how doping with fluorine and temperature variations affect the Raman spectra of NdFeAsO1-xFx superconductors, revealing structural disorder and vibrational mode changes.

Contribution

It provides systematic Raman analysis of NdFeAsO1-xFx with different fluorine levels and temperatures, highlighting doping-induced structural disorder and vibrational property variations.

Findings

Fluorine doping causes structural disorder in Nd-O layers.

High temperature increases the Fe-As vibrational mode coefficient.

Samples contain two phases with distinct Raman features.

Abstract

Raman spectra of polycrystalline NdFeAsO1-xFx (x=0.0, 0.1, 0.2) compound have been systematically investigated as functions of temperature and fluorine concentration. Scanning electron microscopic and Raman microscopic characterization demonstrates that the polycrystalline samples mainly contain two phases, i.e. superconductor NdFeAsO1-xFx compound and a MnP-type FeAs phase, with dissimilar characteristic Raman bands. It was found that fluorine doping leads to structure disorder in the insulator Nd-O layers and high temperature coefficient of Fe-As vibrational mode.