Thermal Expansion of Alkaline‐Doped Lanthanum Ferrite Near the Néel Temperature

Abstract

The thermal expansion and magnetic behaviors of divalent, alkaline-doped lanthanum ferrites (La0.9M0.1FeO3, M=Ca, Sr, Ba) were assessed using a combination of dilatometry, magnetometry, time-of-flight neutron diffraction, and high-temperature X-ray diffraction. Néel temperatures were determined through vibrating sample magnetometry and correlated well with changes in thermal expansion behavior observed during both dilatometry and X-ray diffraction. The Néel temperatures observed for pure, Ca-doped, Sr-doped, and Ba-doped lanthanum ferrites were 471°C, 351°C, 465°C, and 466°C, respectively. The effect of divalent substitutions on the magnetic behavior are attributed to charge compensation mechanisms and structural changes in the material

Combined Theoretical and Experimental Investigations of Atomic Doping To Enhance Photon Absorption and Carrier Transport of LaFeO3 Photocathodes

“…LaFeO 3 has a perovskite structure in which the La atoms are located at the center of a cube composed of eight Fe atoms at the corners that are octahedrally coordinated with O. However, the atoms in LaFeO 3 are slightly displaced from those of an ideal cubic perovskite structure, and LaFeO 3 has an orthorhombic Pnma structure with a G-type antiferromagnetic ordering on the Fe atoms . Theoretically predicted cell parameters for pristine and K-doped LaFeO 3 are shown in Table .…”

k=0Magnetic Structure and Absence of Ferroelectricity inSmFeO3

“…If exchange striction would be an important mechanism in SmFeO 3 one would expect to see also a pyrocurrent signal when the magnetic structure exhibits distinct changes at T SR which is not experimentally observed [1]. Finally, we would like to remark that magneto-elastic effects are not only present in prototypical multiferroic materials like BiFeO 3 [19,20] but (across the doping series Bi 1−x La x FeO 3 [21]) also in non-ferroelectric centrosymmetric materials like LaFeO 3 [22,23]. Our findings suggest that magneto-elastic effects may also lead to an artificial observation of pyrocurrents and, hence, magnetoelastic coupling can easily be misinterpreted as a ferroelectric response.…”

Weakly spin-dependent band structures of antiferromagnetic perovskite LaMO3(M = Cr, Mn, Fe)

“…The z coordinates of O1 and O2 are almost the same as those of La and M, respectively. Available experimental data [12,13,15,16,19] e Reference [19].…”

“…Not only these complex materials but also its mother material, lanthanum manganite (III) (LaMnO 3 ), has been investigated in detail, and it is now well known that LaMnO 3 has a strongly distorted structure [12,13], and shows so-called A-type antiferromagnetic (AFM) ordering below the Néel temperature [12,14,15]. Similarly, lanthanum chromite (LaCrO 3 ) and lanthanum ferrite (LaFeO 3 ) have the same structure as LaMnO 3 [15][16][17][18][19] and they exhibit so-called G-type AFM ordering below the Néel temperature [15]. The OER and ORR of these perovskite materials have been investigated more recently as an application to electrodes [4][5][6].…”