Electronic and magnetic properties of LaNi 1−x Co x O 3 , LaCo 1−x Fe x O 3 and LaNi 1−x Fe x O 3

LaNi 1−x Co x O 3 shows itinerant d-electron behavior similar to LaNiO 3 up to x=0.5. In the range 0.5 3 is not seen when x 1−x Fe x O 3 , itinerancy of d-electrons decreases with increase in x and the compositions with x>0.5 are similar to LaFeO 3 . If x>0.1, the localized-itinerant electron transition is not seen and the cobalt spin state equilibrium is considerably altered. In LaNi 1−x Fe x O 3 , itinerancy decreases with increase in x. These observations can be satisfactorily explained in terms of Goodenough's energy band schemes.