“…Much effort has been dedicated to investigating the effects of doping other elements into CoFe 2 O 4 , including Ti 4+ , Mn 3+ , Cr 3+ , Ge 4+ , Ga 3+ , Si 4+ , etc. [5,6,7,8,9,10]. Nlebedim et al reported that the substitution of Al 3+ for Fe 3+ could result in the decrease of magnetostriction and the change of magnetostrictive coefficient, thus making cobalt–ferrite materials qualified for the sensors and actuators [11,12].…”