Effect of pH and Stirring Speed on the γ-Fe2O3 Material Properties Synthesized from Iron Sand by Using Co-Precipitation Method L. Agusu, Amiruddin -, M. Nalis, S. Misudo, Y. Fujii, Y. Ishikawa, Alimin International Journal of Acta Material Vol. 1 No. 1 2024 DOI 10.62749/ijactmat.v1i1.6