“…Metal-for-Fe substitution in the structure of synthetic iron oxides, prepared in the presence of corresponding foreign metal cations, has been widely reported, especially in the case of goethite, a-FeOOH [14][15][16][17][18]. Incorporation of various metal cations into the structure of iron oxides can affect their electric [19,20], magnetic [21][22][23][24], thermal [23,24], solubility [25], catalytic [26][27][28], adsorption [29,30], gas sensing [31][32][33] and other properties.…”