The hopping between Mn3+ and Mn4+ sites is controlled by the Mn–O–Mn bond angle. The magnetoresistance in 8.5 kOe fields varies from 15 to 25 percent over the temperature range 300 K to 80 K. The conduction mechanism can be understood by using the correlated small polaron model. The ...
For a perfect cubic perovskite, the MOM bond angle is 180°. The relative lengths of the RO and MO bonds determine the stability of the cubic structure. The Goldschmidt tolerance factor t=d(RO)/d(MO)2, where d(RO) and d(MO) are the actual RO and MO bond lengths (that can be ...
Rare-earth manganites exhibit a large set of physical properties, including colossal magnetoresistance, charge-orbital ordering, different magnetic structures and multiferroicity6. Because the magnetism and transport properties of these compounds scale with the Mn-O-Mn bond angle, which defines the balanc...
By tracing the origin of these abundant phenomena, it is the interactions between orbital, charge, spin and lattice degrees of freedom that lie at the core of these correlated oxides. As almost a ubiquitous structural factor in perovskite oxides, oxygen octahedral tilting has received much ...
On the other hand, the structural analysis up to the second coordination shell indicates that the Mn-O-Mn bond angle is the most relevant parameter for understanding the electrical and magnetic properties of these compounds. Finally, an alternative structural mechanism is proposed to explain the ...
The hopping between Mn3+ and Mn4+ sites is controlled by the Mn-O-Mn bond angle. The magnetoresistance in 8.5 kOe fields varies from 15 to 25 percent over the temperature range 300 K to 80 K. The conduction mechanism can be understood by using the correlated small polaron model. The ...
The XPS measurements indicate that the substitution of Pb for Ba does not cause changes in the charge states of the atoms constituting the Pb1-xBax(NO3)(2) crystals. Matching the XPS valence-band spectra and the X-ray emission O Ka bands on a common energy scale indicates that the ...
The signs and magnitudes of the trigonal distortion angles δβ (≈ ?0.3 and 0.4°) related to an ideal octahedron and the local angular variations Δβ related to the host bond angle are suitably illustrated by those of the axial distortion degree (ADD) and the angular variation degree (...
The XPS measurements indicate that the substitution of Pb for Ba does not cause changes in the charge states of the atoms constituting the Pb1-xBax(NO3)2 crystals. Matching the XPS valence-band spectra and the X-ray emission O Kα bands on a common energy scale indicates that the ...
Such gradual suppression of octahedral tilt has been observed for the BiFeO3/(LaSr)MnO3 interface30, where the Fe-O-Fe bond angle was modified over a distance of 10 unit cells by 6° near the interface. Recently a similar suppression of octahedral tilt and its polar effect has been reporte...