Observation of ε - Fe<inf>2</inf>O<inf>3</inf> nanoparticles precipitated in potassium aluminoborate glasses doped with 4 mol % Fe<inf>2</inf>O<inf>3</inf>

Abstract

© 2019 Elsevier Ltd Microstructural and magnetic properties of potassium aluminoborate glasses 25K2O–25Al2O3–50B2O3 (KAB): 4% Fe2O3(composition in mol %)are studied in a wide temperature range from 4.2 up 690 K by magnetometry, Mössbauer spectroscopy and electron spin resonance (ESR). Two samples of KAB: 4% Fe2O3 before (Sample I)and after annealing (Sample II)at T = 525oC are studied. Based on all obtained experimental data we can conclude that only paramagnetic impurity iron centers were formed in the Sample I, while the additional hematite and ε - Fe2O3 nanoparticles were formed in the Sample II after annealing above the glass transition temperature.