Disorder induced magnetism and electrical conduction in La doped Ca2FeMoO6 double perovskite

Abstract

We report the magnetism and electrical transport properties of La doped Ca2FeMoO6 double perovskite. Reduction in magnetic moment, nonmonotonic variation in magnetic ordering temperature (TC), increasing magnetic hardness, low temperature resistivity upturn, and loss of metallic conductivity are some of the major changes that we observed due to La doping induced disorder in double perovskite structure. The increase in magnetic disorder in La doped samples and its effect on TC is more consistent with the mean field theory. The modification in electronic band structure due to La doping is understood by establishing a correlation between the temperature dependence of electrical conductivity and thermoelectric power.

Magnetic field mediated low-temperature resistivity upturn in electron-doped La1−xHfxMnO3 manganite oxides

“…The same result was also found in other magnetic oxides by increasing the doping level of nonmagnetic elements. 26 Our results may be different from the explanation on the polycrystalline La 0.5 Pb 0.5 MnO 3 compounds in Ref. 8.…”

Signature of an antiferromagnetic metallic ground state in heavily electron-doped Sr2FeMoO6

“…This behavior is consistent with the literature, at least for the La 1.0 sample, 5,16,17 and is generally explained by an enhanced contribution from superexchange driven Fe-O-Fe AFM interaction, resulting from increased antisite disorder with doping. 18,19 However, the trend of the M(H ) curves indicates a sharp change after Fig. 3(b).…”

“…This behavior is consistent with the literature, at least for the La 1.0 sample, 6,12,13 and is generally explained by enhanced contribution from superexchange driven Fe-O-Fe AFM interaction, resulting from increased anti-site disorder with doping. 14,15 However, the trend of the M (H) curves indicate a sharp change after x = 1.1 and the M (H) curve already becomes nearly linear for x = 1.25, although a finite hysteresis persists (see inset). The magnetic coercivity gradually decreases with increasing x and the M (H) from La 1.5 sample closely resembles an antiferromagnetic M (H) curve.…”

Effects of the band-filling and Fe/Mo disorder on physical properties of Ca 2 FeMoO 6

“…1(a). It can be clearly seen that all the diffraction peaks are well consistent with double perovskite structure with a monoclinic phase and a space group of P2 1 /n and no second phase is detectable, [21][22][23][24][25] which means that the C1-C6 samples are single-phased. The superstructure diffracted peaks of {110} resulting from the ordered arrangement of Fe and Mo cations at the B-sites are particularly sensitive to Fe/Mo ordering degree.…”