Doping effects on structural and magnetic evolutions of orthoferrite SmFe _{(1− x )} Al _x O ₃

Abstract

The structural and magnetic properties of SmFeO 3 with B site substitution of non-magnetic atom Al are investigated. The x-ray diffraction patterns show that SmFe (1−x) Al x O 3 remains an orthorhombic structure within the whole doping range, and the unit-cell volume decreases monotonically with the increase of doped Al concentration. Besides, the octahedral tilting distortions of FeO 6 are found to be alleviated while the tolerance factor increases. However, the relationship between the lattice parameters and Al concentration is observed to deviate from Vegard's rule, and this may be caused by magnetostriction effects. For the doping content values in a range 0 ≤ x ≤ 0.6, the ferromagnetism, antiferromagnetism, and paramagnetism are observed to occur continuously. Moreover, the magnetization and the spin reorientation temperature (T k ) decrease monotonically as Al content value increases. With the doping content values being x = 0.8 and 1.0, these compounds only show paramagnetic behavior.

Effect of B-site Co substitution on the structure and magnetic properties of nanocrystalline neodymium orthoferrite synthesized by auto-combustion

“…Generally, the mismatch between the Nd─O and Fe─O bond lengths introduces internal stresses which result in tilting of the FeO 6 octahedra. The Fe-O-Fe bond angle is a measure of the tilting of the octahedron [26][27][28]. This is seen in the Fe─O─Fe angles in all the samples being less than ideal cubic perovskite value of 180°.…”

“…There are four Fe 3+ ions per unit cell. Each Fe 3+ ion is surrounded by six O 2− ions forming an octahedron while the Nd 3+ ions fit in the interstices of the FeO 6 octahedra in dodecahedral coordination [26]. Co 3+ ions enter the Fe 3+ ions site in the doped samples.…”

“…Some distortions may exist in the ideal cubic perovskite, to result in the formation of orthorhombic, rhombohedral, hexagonal and tetragonal forms. These distortions arise from three aspects: (i) sizes of the cations, (ii) deviations from the ideal composition, and (iii) Jahn-Teller effect [25,26]. The differences in the cation sizes could be evaluated by the Goldschmidt's tolerance factor [25].…”

Influence of Temperature on Anaerobic Co-digestion of Dairy Manure and Edible Mushroom Cultivation Waste

“…China is a large agricultural country and produces an enormous amount of animal products and edible mushroom products each year, meanwhile large quantity of animal manure and edible mushroom cultivation waste are produced [3]. With transformation of rural life style and agricultural production mode in recent years, animal manure and edible mushroom cultivation waste could not be used efficiently and large quantities of these matters were abandoned at random [4].…”

Manganese substitution effects in SmFeO3 nanoparticles fabricated by self-ignited sol–gel process

“…For SmFe 1-x Ti x O 3 , the interaction between Sm-4f and Fe-3d electrons is effectively enhanced, which weakens the total magnetization and considerably suppresses the weak ferromagnetism of Fe sublattice starting from 260 K [11]. When SmFeO 3 was doped by non-magnetic atom Al in B site, the magnetization and the spin-reorientation temperature decrease monotonically as Al content value increases [12]. The substitution of manganese by iron will be also interesting, because Mn 3?…”