Enhancement of low-field magnetoresistance in polycrystalline Sr2FeMoO6 with Al doping

Abstract

Polycrystalline Sr2Fe1−xAlxMoO6 compounds with x=0, 0.05, 0.10, 0.15, and 0.30 were fabricated and their low-field magnetoresistance (LFMR) performance studied. The LFMR was greatly enhanced as x increased from nil to 0.15, and its origin was found to be intragranular spin-dependent scattering. The replacement of Fe by Al weakened the antiferromagnetic exchange in the antiphase boundary arising from the antisite defect and acted as a barrier for electron transport along the Mo–O–Fe–O–Mo–O–Fe chain in the ferromagnetic segregation and weakened the ferromagnetic exchange. When the external magnetic field was applied, the spin in the antiphase boundary appeared to align more easily to the external field after Al doping and the transport of the electron was easier due to the weakening of the double exchange barrier.

Spintronics and spintronics materials

“…229 Doping with Al permits an increase in the magnetoresistance of Sr 2 Fe 1-x Al x MoO 6 (x = 0.15) to nearly 60% at 5 К (H = 1 T) and improve ment of electron transport properties. 230 Differences between the crystal structures of normal semiconductors GaAs and Si and the CMS or semimetals and half metals prevent the latter from being integrated into semiconductor heterostructures for spintronics ap plications.…”

Effect of doping Zn on the magnetoresistance of polycrystalline Sr2FeMoO6

“…It is well known that the magnetic structure, especially the anti-site defects, can be changed notably by doping at Fe site, thus the work about substitution of Fe ion should be more helpful for understanding the correlation between magnetic structure and magnet-transport in SFMO. Some works, such as doping Cr, V, Mn, Ni, Co, Cu and Al ions at Fe site in SFMO [13][14][15][16][17][18][19][20][21], have been reported. Furthermore, both intragrain MR and intergrain MR at low temperature were observed in the Ba 2 Fe 1−x M x MoO 6 (M = Mn, Zn) compacts by Sriti et al [22].…”

Structural and magnetic properties of Sr2Fe1−xGaxMoO6 (0≤x≤0.25)

“…Since all the samples were processed simultaneously, so the preparation condition for the samples is exactly alike. Hence, the appreciable increase in MR for Ga-doping systems is thought to weaken the double exchange barrier after Ga doping in SFMO system [27]. In such a case, Ga ions may act as a barrier for electron transport along the chain in the ferromagnetic segregation and weaken the ferromagnetic exchange.…”