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Journal of Advanced Ceramics

Keywords

magnetic materials, X-ray diffraction (XRD), Raman spectra, Mössbauer spectroscopy

Abstract

Solid-state ceramic technique route is used for synthesizing Cr-doped haematite α-Fe2-xCrxO3 (x = 0, 0.125, 0.50 and 1) samples. Single phase and corundum (Al2O3) type structure is revealed from the X-ray diffraction (XRD) patterns. The Raman spectra of α-Fe2-xCrxO3 illustrate seven phonon modes. On substitution of Cr (x = 0, 0.125, 0.50 and 1) at Fe site, all Raman active modes are shifted to higher wave numbers. The coercivity and remanence of Cr-doped haematites increase as x increases. The increased coercivity and remanence for Cr-doped samples can be attributed to their enhanced shape and magneto-crystalline anisotropy. The observed isomer shift δ values from room-temperature Mössbauer data clearly show the presence of ferric (Fe3+) and Cr3+ ions illustrating strong ferromagnetic ordering up to x = 0.125 in α-Fe2-xCrxO3 haematite and weak ferromagnetic ordering for α-Fe2-xCrxO3 (x > 0.125) haematites.

Publisher

Tsinghua University Press

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