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

Abstract

We report about the physical properties of samples obtained by different substitutions on the Mn site of LaMnO 3 : LaMn 0.85 Ni 0.15 O 3 , LaMn 0.85 Ga 0.15 O 3 and LaMn 0.5 Ga 0.5 O 3 . It is well known that the antiferromagnetic orbitally-ordered ground-state of LaMnO 3 is easily destroyed to give way to ferromagnetism. However, this ferromagnetic behaviour can result from several mechanisms : depending on the nature of the substituting cation and on the substitution level, the physical properties derive from a complex interplay between exchange interactions, orbital ordering and Jahn-Teller distortion. As a result, there are noticeable differences between the physical properties of the different samples, even though all three samples display a ferromagnetic component in zero applied magnetic field. In this paper we compare the crystallographic, electrical and magnetic properties of these samples, with a special attention for the AC susceptibility behaviour.

Effect of oxygen non-stoichiometry on the structural and magnetotransport properties of LaMn0.85Cr0.15O3+δ

“…This last result rules out the presence of clusters giving rise to the observed MR. In previously reported results on LaMn 1Àx B x O 3+d (B ¼ Zn, Li, Co, Ga, Sn), the absence of MR in the paramagnetic region [7][8][9] was found. Furthermore, in case of non-magnetic ions such as Ga and Sn (where magnetic interactions are clearly not established), MR effect was not found in the whole range of studied temperatures [7,9].…”

“…In previously reported results on LaMn 1Àx B x O 3+d (B ¼ Zn, Li, Co, Ga, Sn), the absence of MR in the paramagnetic region [7][8][9] was found. Furthermore, in case of non-magnetic ions such as Ga and Sn (where magnetic interactions are clearly not established), MR effect was not found in the whole range of studied temperatures [7,9]. The parent stoichiometric compound LaMnO 3.00 does not present MR either in the whole range of temperatures [35] including the paramagnetic region.…”

“…alters the magnetic interactions in the Mn-O network and therefore the magnetic phase diagram. For this reason, these substitutions have been extensively studied [6][7][8][9]. This is also another way to fully understand the origin of the magnetoresistance effect.…”

The investigation of structural and vibrational properties and optical behavior of Ti-doped La0.67Ba0.25Ca0.08Mn(1−x)TixO3 (x = 0.00, 0.05 and 0.10) manganites

“…This increase affirmed the incorporation of Ti (r Ti 4+ ¼ 0.605 A) at the Mn site and the ratio can explain the anisotropic contractions. 26,27 The results of the structural renement conrmed the rhombohedral phase R 3c (no. 167), where (La/Ba/Ca) are at the 6a (0, 0, 1/4) position, (Mn/Ti) at 6b (0, 0, 0) and O at 18e (x, 0, 1/4).…”

Unusual features of nitrogen substitutions in silicene

“…For example, rare earth layers, with thicknesses ranging from a thin lm down to a monolayer, are shown to present a dramatic antiferromagnetism to ferromagnetism transition. 30 That is, a class of robust 2D magnets is generated in the synthesis. On the theoretical side, rst-principles calculations are utilized to explore the substitution-and adsorption-enriched essential properties, e.g., the diverse phenomena in N-, B-, C-, Al-, P-, 31 transition-metal-, 23 CO 2 -/H 2 S-/SO 2 -containing silicene systems.…”