Magnetic properties of Ga-doped lanthanum manganite with controlled oxygen stoichometry

Abstract

Stoichiometric LaMnO 3 is an insulator whose A-type antiferromagnetic structure at low temperature is mainly connected to the Jahn-Teller distortion of the MnO 6 octahedra. The substitution of non magnetic d 10 Ga 3+ ions on the manganese site disrupts the orbital and spin orderings of the manganese ions and has a strong influence on the physical properties. The antiferromagnetic order is progressively destroyed while the ferromagnetic component increases. At the same time, the distortion of the orthorhombic cell decreases and the high temperature structural Jahn-Teller transition disappears. Such studies on manganese site substitutions give insight into the physics of the Mn-O three-dimensional network, which is supposed to be the key feature in the CMR manganites.

Effect of Ga doping on magneto-transport properties in colossal magnetoresistive La0.7Ca0.3Mn1−xGaxO3 (0<x<0.1)

“…Due to these specific characteristics, Ga-substituted manganites have often been used as a model system for studying super-exchange interactions in LaMnO 3 (see Refs. [14][15][16][17][18][19][20][21][22]). Meera et al [18] and Yusuf et al [19] studied the magnetic properties of La 0.67 Ca 0.33 Mn 1Ày Ga y O 3 samples with y ¼ 0.1.…”

Ferromagnetic Double Perovskite Semiconductors with Tunable Properties

“…Although the Mn‐doped disordered single perovskite LaGa 1− x Mn x O 3 series has been well‐studied, [ 41 , 42 , 43 , 44 , 45 ] samples of this series in the composition range 0.1 ≤ x ≤ 0.5 were characterized magnetically as a comparison to the Mn‐doped double perovskite. The magnetization data were scaled to their equivalent double perovskite values (i.e., for La 2 Ga 2−2 x Mn 2 x O 6 ) for consistency.…”

“…The isothermal magnetization data at 300 and 2 K are consistent with the temperature‐dependent magnetization data and are in good agreement with the literature. [ 41 , 43 , 45 ] The magnetization data collected from double‐ and single‐perovskites with 40% total Mn‐concentration on the B‐sites (LaGa 0.6 Mn 0.4 O 3 and Sr 2 Ga 0.2 Mn 0.8 SbO 6 ) are stacked in Figure 3c,d , as representative data. The temperature‐dependent magnetic susceptibility curves coincide with each other in the temperature range 150 ≤ T / K ≤ 300, while they differ significantly at lower temperatures.…”

“…The isothermal magnetization data collected from the Mn-doped materials at 300 K as a function of applied field is linear and passes through the origin, with a small positive slope, while analogous data collected at 2 K have positive slopes as well, but start to exhibit easily observed hysteresis at 30% Mn-doping, serving as strong evidence of ferromagnetic behavior, consistent with the temperature-dependent magnetization data. Although the Mn-doped disordered single perovskite LaGa 1−x Mn x O 3 series has been well-studied, [41][42][43][44][45] samples of this series in the composition range 0.1 ≤ x ≤ 0.5 were characterized magnetically as a comparison to the Mn-doped double perovskite. The magnetization data were scaled to their equivalent double perovskite values (i.e., for La 2 Ga 2−2x Mn 2x O 6 ) for consistency.…”

Magnetic and electronic ground states of B-site-substituted LaMnO3: from antiferromagnetism to ferromagnetism

“…Since Ga 3+ is isovalent to Mn 3+ , Ga-susbtituted manganites are often used as a model system for studying super-exchange interactions [22][23][24][25]. On the contrary, substitution by Ni 2+ leads to the appearance of Mn 4+ species and to double exchange interactions between Mn 3+ and Mn 4+ ions [26][27][28][29].…”