The magnetic and transport behaviours of the La0.7-xGdxSr0.3MnO3 (0≤x≤0.70) system are investigated. The experimental results indicate that with increasing Gd doping content, the magnetism of the system changes from...The magnetic and transport behaviours of the La0.7-xGdxSr0.3MnO3 (0≤x≤0.70) system are investigated. The experimental results indicate that with increasing Gd doping content, the magnetism of the system changes from the long-range ferromagnetic order state to the cluster-spin glass state, then to the antiferromagnetic (AFM) state. It is interesting that the phase separation appears at x=0.30 and 0.40 and disappears for x _>0.50 where the AFM state occurs. At high doping content, the transport behaviours exhibit abnormality, e.g. there are two temperature ranges in which the p-T curves can be well fitted by a variable-range hopping (VRH) model. We suggest that the VRH does not come from the hopping of carriers between clusters, but from the different magnetic backgrounds in the clusters.展开更多
La0.14Pr0.56Sr0.3MnO3/SrTiO3 and La0.7Ca0.3MnO3/Gd0.7Ca0.3MnO3 multilayers have been fabricated by using pulsed laser deposition. The insulator-metal transition temperatures of the multilayers decrease with the decrea...La0.14Pr0.56Sr0.3MnO3/SrTiO3 and La0.7Ca0.3MnO3/Gd0.7Ca0.3MnO3 multilayers have been fabricated by using pulsed laser deposition. The insulator-metal transition temperatures of the multilayers decrease with the decreasing thickness of the ferromagnetic layers. It is confirmed from the experiment and analysis that a nonferromagnetic insulating region exists near the interface, which could not be attributed to the roughness of the growth surfaces and disorder of the ferromagnetic layers.展开更多
Ferroelectrics and colossal magnetoresistance heterostructure Ba1-χSrχTiO3 (BST)/La1-χSrχMnO3 (LSMO) havebeen fabricated on a LaAlOa substrate by the pulse laser deposition method. The dielectric measurements show...Ferroelectrics and colossal magnetoresistance heterostructure Ba1-χSrχTiO3 (BST)/La1-χSrχMnO3 (LSMO) havebeen fabricated on a LaAlOa substrate by the pulse laser deposition method. The dielectric measurements showthat at room temperature and 100 kHz, the dielectric constant and loss tangent are about 990 and 0.012, respec-tively; the highest tunability is about 45% near 200 K under the applied electric field of 200 k V/cm. Further studyindicates that the leakage current for the BST/LSMO heterostructure obeys the Schottky emission mechanismin the electric field region higher than 100 k V/cm at room temperature.展开更多
文摘The magnetic and transport behaviours of the La0.7-xGdxSr0.3MnO3 (0≤x≤0.70) system are investigated. The experimental results indicate that with increasing Gd doping content, the magnetism of the system changes from the long-range ferromagnetic order state to the cluster-spin glass state, then to the antiferromagnetic (AFM) state. It is interesting that the phase separation appears at x=0.30 and 0.40 and disappears for x _>0.50 where the AFM state occurs. At high doping content, the transport behaviours exhibit abnormality, e.g. there are two temperature ranges in which the p-T curves can be well fitted by a variable-range hopping (VRH) model. We suggest that the VRH does not come from the hopping of carriers between clusters, but from the different magnetic backgrounds in the clusters.
文摘La0.14Pr0.56Sr0.3MnO3/SrTiO3 and La0.7Ca0.3MnO3/Gd0.7Ca0.3MnO3 multilayers have been fabricated by using pulsed laser deposition. The insulator-metal transition temperatures of the multilayers decrease with the decreasing thickness of the ferromagnetic layers. It is confirmed from the experiment and analysis that a nonferromagnetic insulating region exists near the interface, which could not be attributed to the roughness of the growth surfaces and disorder of the ferromagnetic layers.
文摘Ferroelectrics and colossal magnetoresistance heterostructure Ba1-χSrχTiO3 (BST)/La1-χSrχMnO3 (LSMO) havebeen fabricated on a LaAlOa substrate by the pulse laser deposition method. The dielectric measurements showthat at room temperature and 100 kHz, the dielectric constant and loss tangent are about 990 and 0.012, respec-tively; the highest tunability is about 45% near 200 K under the applied electric field of 200 k V/cm. Further studyindicates that the leakage current for the BST/LSMO heterostructure obeys the Schottky emission mechanismin the electric field region higher than 100 k V/cm at room temperature.
