Structure dependence of the ferromagnetic transition temperature in rhombohedralLa1−x

Makoto Itoh

¹

,

Tetsuo Shimura

²

,

Jingxiong Yu

³

et al.

Synthesis, structural and ferromagnetic properties of La1−x K x MnO3 (0·0 ≤ x ≤ 0·25) phases by solution combustion method

“…It is possible to achieve an equal amount of hole doping with half the number of the monovalent ions, because for the same amount of aliovalent dopant the hole density is twice that of the divalent ion doping. Monovalent ion-doped rare earth manganites of the general formula, Ln 1-x A x MnO 3 (Ln = La, Pr, Nd; A = Na, K, Rb), provide another series of oxides to study the physical phenomena of insulator-to-metal transition and colossal magnetoresistance (Itoh et al 1995;Shimura et al 1996;Chen and de Lozanne 1997;Ng-Lee et al 1997;Sahana et al 1997;Singh et al 1998). Alkali metal ion doped lanthanum manganites have been prepared by the conventional ceramic methods (Itoh et al 1995;Shimura et al 1996), alkali-flux method (Singh et al 1998;Shivakumara et al 2004) and fused salt electrolysis (McCarroll et al 1999).…”

Structure, magnetic and electrical properties of La0.6Sr0.4−xKxMnO3 perovskites

“…Recently some studies of manganites doped with monovalent alkali-metal ions have been reported [18][19][20]. These compounds crystallize in a rhombohedral distorted perovskite structure with space group R3c [21] and exhibit both paramagnetic-ferromagnetic and semiconductor-metallic transitions with decreasing temperature.…”

Electroresistance of La0.8Li0.2MnO3

“…1-5͒ and, more broadly, lanthanum manganites doped with other monovalent on divalent ions on either the A or the B site. [8][9][10][11]20,21 Various explanations have been advanced for this rich structure reported in the R-T curves in the lanthanum manganites including grain-size effects, 22 oxidation, 23 percolative phase separation, 24 and phase inhomogeneity. 4 In the present case, it is thought to arise from the grain boundaries in the sample.…”