Bi doping effects on the physical properties of Pr0.6Sr0.4Mn1−xBixO3 (0≤x≤0.2) manganese oxides

Electrical conduction and thermal properties of Bi-doped Pr0·7Sr0·3MnO3 manganite

“…An important parameter entropy ( S) associated with FM transition, can be obtained by integrating the area under C mag /T vs T curves. It is satisfactory to note that the present results are in agreement with those reported for parent compound (Kammoun et al 2008;Agarwal et al 2010). With Bi-doping, entropy slightly decreases from 2·06 J/mol K (pristine sample) to 1·63, 1·45 J/mol K for x = 0·15 and 0·25 compounds, respectively.…”

“…Like other electrical, magnetic and thermal measurements, κ also confirms enhancement of transition temperature with Bi 3+ ion doping. At room temperature, the observed magnitude of κ is ∼27·4, 25·4 and 22·6 mW/cm K, these values are one order smaller than high temperature superconductors and are well in agreement with previous reports (Kammoun et al 2008;Agarwal et al 2010). Such small κ values increasing with temperature are well studied in manganites and can be explained in terms of magnetic polaron or dynamic JT distortion (Cohn et al 1997;Visser et al 1997).…”

“…Gencer et al (2005) reported an entropy ( S) of ∼3·5 J/kgK under 1 T field in La 0·62 Bi 0·05 Ca 0·33 MnO 3 compound and in a similar manner Bi-doping in La 0·7 Sr 0·3 MnO 3 enhances magnetic refrigeration capacity and attains higher value ( S) of ∼5·02 J/kgK (Gencer et al 2005;Barik and Mahendiran 2010). Bi 3+ ion at Mn site have been studied several times, but there are less reports on 'A' site substitution even though Bi 3+ (1·17 Å) and Pr 3+ (1·126 Å) ions have nearly same ionic radii (Kammoun et al 2008;Zhang et al 2010). Recently, we have reported electrical and magnetic properties of Bi-doped PSMO compound (Neeraj Kumar et al 2010).…”

Influence of Sn-doping on Magnetocaloric Properties of La0.7Ca0.3Mn1−xSnxO3(x = 0.0, x = 0.02 and x = 0.04) Compounds

“…This phenomenon could be described as a weakening of the spinlattice coupling in the matrix sample which affected ferromagnetic behavior (Phan et al, 2004). This weakening of the ferromagnetic regime corresponds to the weakening in the DoubleExchange (DE) mechanism as is also found in other metals Bi-doped (Kammoun et al, 2008a, Kammoun et al, 2008b, Sn-doped (Dhahri et al, 2008), and Ga-doped (Omri et al, 2012) in B-site atomic position. = 0.53Å) will introduce a mismatch in the structure, due to difference of the ionic radius (Dhahri et al, 2008).…”

Transport and magnetoresistance in double-doped La(2+x)/3Sr(1−x)/3FexMn1−xO3 films

“…Most research is focused on the A-site or RE-site doping and there is less research on the Mn-site doping. However, the effect of Mn-site doping on the transport properties of manganites is very important because it directly affect the double exchange interaction by modifying the Mn 3+ and Mn 4+ network [14][15][16]. The doped element at Mn site, such as Cr, Co and Ni, induces an increase of the resistance because it changes the Mn 3+ /Mn 4+ ratio [17][18][19][20].…”