Influence of Mn and Cu on the properties of BiFeO3 thin films

Abstract

A Mn and Cu co-doping BiFeO3 (BFO) thin film was fabricated on FTO/glass substrate by sol-gel method with a sequential layer deposition process. The raw materials using in the starting solution were bismuth nitrate pentahydrate (Bi(NO3)3·5H2O), iron(III) nitrate nonahydrate (Fe(NO3)3·9H2O). Manganese (II) acetate tetrahydrate (C4H6MnO4·4H2O) and copper (II) acetate monohydrate ((Ch3COO)2Cu·H2O) were used as dopants. All of these previous reagents were mixed together using ethylene glycol (HOCH2CH2OH) as solvent. The atomic ratio used was BiFe0.94Mn0.04Cu0.02O3 (BFMCO) and 5 mol% of excess of bismuth was employed to compensate its volatility during high temperature annealing. The structural, morphological, optical properties and the charge transport mechanisms of the sample were studied using X-rays Diffraction (XRD), Scanning Electron Microscopy (SEM) and UV-visible spectroscopy, respectively. The chemical composition was studied by X-ray Photoelectron Spectroscopy (XPS). Simultaneously, a comparison was made between BFO and BFMCO thin films, prepared and characterized by the same experimental process, which allowed and knowing the effect of Cu and Mn co-doping on the structure and physical properties of BFO.