Magnetic transitions and electrical transport in Bi-doped lanthanum strontium manganites

Abstract

The temperature dependence of the electrical resistivity ρ, thermoelectric power S and the magnetic susceptibility χ of La 0.7-x Bi x Sr 0.3 MnO 3 (x = 0.05, 0.10, and 0.15 at.%) manganites were investigated. La 0.7-x Bi x Sr 0.3 MnO 3 crystallizes in a single phase rhombohedral structure with parasitic phase inclusions. With increasing Bi concentration, a systematic decrease in the ferromagnetic transition temperature (T C ), the metal-semiconducting transition temperature (T ms1 ) and also the values of activation energies E ρ and E S from ρ(T) and S(T) were observed. On the other hand, in the high-temperature (T > T ms ) paramagnetic semiconductor regime, the adiabatic small polaron hopping model fit well, thereby indicating that polaron hopping might be responsible for the conduction mechanism. In addition, the thermoelectric power data at low temperatures were analyzed by considering both the magnon and the phonon drag concept, while the high-temperature data were confirmed a small polaron hopping conduction mechanism.

Enhanced electro-magnetic properties in La0.7Sr0.3MnO3/ZrO2 composites

“…As could be seen in Table 2, generally there is a decrease in N(E F ) due to the increase in resistivity. The data have fitted to SPH in temperature range T [ h D /2 [20][21][22]. The SPH model gives:…”

Electron Spin Resonance in Ceramic Samples of Lanthanum—Bismuth Manganite La$_{0.925}$Bi$_{0.075}$MnO$_{3}$

“…Проте, основна увага в згаданих роботах приділялася магнетокалоричним властивостям сполуки. Дослідження впливу леґування в області малих концентрацій Bi ( 5%) на транспортні властивості лантан-стронційового манганіту було виконано в роботі [21]. Результати роботи в цілому підтверджують існування широкої температурної области, в якій відбувається перехід з парамагнетної у феромагнетну фазу, а також зменшення провідности та температури переходу провідник-напівпровідник.…”

Flux-Mediated Doping of Bi into (La,Sr)MnO3 Films Grown on NdGdO3 (110) Substrates

“…When we focus on the doping into LSMO, there are several reported effects that the doping of various rare-earth elements such as Pr, Eu, and Bi for La has on its physicochemical properties . Among them, Bi-doped (La,Sr)­MnO 3 (BLSMO) has captivated researchers due to its large magnetoresistance (MR) ratio and large magnetocaloric effect (MCE), − and the latter would be useful for magnetic refrigerators, which are attracting much attention as a clean cooling system with a lower environmental loading. In fact, BLSMO is expected to show a large MCE effect accompanying its first-order phase transition. , There have, therefore, been reported many studies on the powder forms of BLSMO, but have scarcely investigated its epitaxial thin-film forms so far.…”