Magnetic field dependence of the magnetic phase separation in Pr1-xCaxMnO3 manganites studied by small-angle neutron scattering

Abstract

Transport properties of manganese oxides suggest that their colossal magnetoresistance (CMR) is due to percolation between ferromagnetic metallic (FM) clusters in an antiferromagnetic insulating (AFI) matrix. We have studied small-angle neutron scattering under applied magnetic field in CMR Pr1-xCaxMnO3 crystals for x around 0.33. Quantitative analysis of the small-angle magnetic neutron scattering shows that the magnetic heterogeneities take place at different scales. At the mesoscopic scale (200nm), the inhomogeneities correspond to the percolation of the conducting ferromagnetic phase into the insulating phases. It is at the origin of the colossal magnetoresistance of the compound. The other inhomogeneities are nanoscopic: inside the antiferromagnetic phase (AFI), there exist small ferromagnetic clusters. Inside the ferromagnetic phase which exists in absence of magnetic field in some compounds and is in fact insulating (FI), there also exist small non ferromagnetic objects. No evolution of this nanostructure is observed when the magnetic field is applied. The existence of such nanoscale objects is discussed in relation to the cationic disorder of these compounds.

References in corpus (13)

• Explanation of Giant Cluster Coexistence in Doped Manganites and Other Compounds
• Resistivity of Mixed-Phase Manganites
• Relevance of Cooperative Lattice Effects and Correlated Disorder in Phase-Separation Theories for CMR Manganites
• Mesoscopic and Microscopic Phase Segregation in Manganese Perovskites
• Elastic interaction and superstructures in manganites and other Jahn-Teller systems
• Why stripes? Spontaneous formation of inhomogeneous structures due to elastic interactions
• Phase separation, percolation and giant isotope effect in manganites
• Microphase separation in Pr0.67Ca0.33MnO3 by small angle neutron scattering
• Non-linear effects and Joule heating in I-V curves in manganites
• Study of Percolative Transitions with First-Order Characteristics in the Context of CMR Manganites
• Neutron scattering evidence for magnetic field driven abrupt magnetic and structural transitions in a phase separated manganite
• Field dependence of the electronic phase separation in Pr0.67Ca0.33MnO3 by small angle magnetic neutron scattering
• Nanoscale phase separation in manganites

Cited by in corpus (9)

• Nanoscale magnetic structure of ferromagnet/antiferromagnet manganite multilayers
• Magnetic states and spin-glass properties in Bi0.67Ca0.33MnO3: macroscopic ac measurements and neutron scattering
• Dielectric catastrophe at the magnetic field induced insulator to metal transition in Pr1-xCaxMnO3 (x=0.30, 0.37) crystals
• Inhomogeneous ferrimagnetic-like behavior in Gd2/3Ca1/3MnO3 single crystals
• Magnetic properties of the insulating ferromagnetic phase in strained Pr_0.6Ca_0.4MnO_3 thin films
• Small angle neutron scattering study of the step-like magnetic transformation in Pr0.70Ca0.30MnO3
• Ultrafast photoinduced phase separation dynamics in Pr(0.6)Ca(0.4)MnO(3) thin films
• Direct observation of magnetic phase coexistence and magnetization reversal in a Gd${}_{0.67}$Ca${}_{0.33}$MnO${}_3$ thin film
• Temperature and fluence dependence of ultrafast phase separation dynamics in Pr0.6Ca0.4MnO3 thin films