Fig. 5

Magnetic parameters of hysteresis loops of samples of spinel-type nanosized Zn–Fe–O oxides isothermally heated at about (1) 60, (2) 100, (3) 200, (4) 300, (5) 400, (6) 500, (7) 600, (8) 650, (9) 700, (10) 800, (11) 900, and (12) 950 °C for 2 h.