On the coexistence of spin and lattice polarons in the La0.67−xEuxCa0.33MnO3 CMR system

Effect of Eu doping on structural and magneto-electrical properties of La0.7Ca0.3MnO3 manganites

“…Both samples are found to exhibit a metal-insulator transition in the studied temperature range. Compliant with other systems previously studied [19,33,34], the metal-insulator transition temperature T p is found to decrease with Eu doping from 194 to 165 K (Table 1). Also and as it can be seen from the same figure, the resistivity of the doped sample is twice larger than that of the undoped one.…”

“…The effect of Eu doping at A-site of manganites has been studied by many groups. In fact, Reddy et al [19] showed that the Eu doped La 0.67−x Eu x Ca 0.33 MnO 3 compounds with x ≤ 0.29 exhibit lower Curie and insulator-metal transition temperatures with respect to the undoped sample in addition to possessing CMR property. Similar results have been reported too by several groups in Sm, K and Gd doped CMR manganites [20][21][22].…”

151Eu Mössbauer studies on La0.5Eu0.17Ca0.33MnO3 CMR system

“…In recent studies it is observed that a Griffith's like phase exists above the T C , with short-range magnetic correlations in paramagnetic insulating region [6][7][8]. In our recent study we have shown that the short range magnetic correlations above the MI transition temperature promote the coupling of spins to charge localization, thus leading to the coexistence of the lattice and spin polarons in PM region [9]. Spectroscopic studies based on neutron [10], EXAFs [11], µSR [12] reveals the role of JT phonons is vital in controlling the electrical transport.…”

151Eu Mössbauer Spectroscopy in La0.38Eu0.29Ca0.33MnO3

“…Partial replacement of La by Eu in this system is expected to reveal the role of spin and lattice polarons around the metalYinsulator transition as the existence of small polarons in the insulating paramagnetic phase was questioned based on 57 Fe Mössbauer studies [13]. In our recent studies, it was confirmed through Eu substituted system that small-and spin-polarons do coexist around the metalYinsulator transition [14]. In this context an attempt to understand the role of the JYT distortions in the La 0.38 Eu 0.29 Ca 0.33 MnO 3 system is made through 151 Eu Mössbauer studies along with electrical and magnetic transport measurements.…”

“…In this report the results on the sample with x = 0.29 is being presented, as other concentrations of Eu yielded normal CMR system with huge resistivity cusp [14]. The phase purity and crystal structure of the synthesised samples were examined by the step scanned powder diffraction pattern recorded at 300 K using Siemens D5000 diffractometer with the Cu Ka radiation.…”