Low-Field Colossal Magnetoresistance in Manganite Tunnel Junctions

1997 ◽  
Vol 494 ◽  
Author(s):  
J. Nassar ◽  
M. Viret ◽  
M. Drouet ◽  
J. P. Contour ◽  
C. Fermon ◽  
...  

ABSTRACTLarge magnetoresistance values are obtained on tunnel junctions epitaxially deposited by pulsed-laser deposition and consisting of ferromagnetic manganite La0.67Sr0.33MnO3 electrodes separated by various tunnel barriers: SrTiO3, PrBaCu2.8Ga0.2O7 and CeO2. The magnetoresistance can be decomposed into a low-field and a high-field contribution. The latter is attributed to the presence of canted interfacial manganite phases, as confirmed by the temperature behaviour of the resistance. A low-field magnetoresistance ratio of 450% below 100 Oe is obtained on a sample with a SrTiO3 barrier, indicating a spin polarization value in excess of 0.83 for the manganite.

2008 ◽  
Vol 53 (9(5)) ◽  
pp. 2427-2430 ◽  
Author(s):  
N.V. Dai ◽  
N.C. Thuan ◽  
L.V. Hong ◽  
N.X. Phuc ◽  
Y.P. Lee

2004 ◽  
Vol 811 ◽  
Author(s):  
Rickard Fors ◽  
Annika Pohl ◽  
Sergey Khartsev ◽  
Alexander Grishin ◽  
Gunnar Westin

ABSTRACTEpitaxial La0.67Ca0.33MnO3 films have been prepared on LaAlO3 crystals by pulsed laser deposition (PLD) and by a novel all-alkoxide sol-gel technique. Different out-of-plane lattice parameters are found for the as-prepared films, and scanning electron microscopy shows a more porous structure for sol-gel films as compared to PLD films. These differences are largely removed by post-annealing at 1000 °C. Transport measurements show maximum temperature coefficient of resistivity of 8.2 % K−1 at 258 K (PLD) and 6.1 % K−1 at 241 K (sol-gel) and colossal magnetoresistance at 7 kOe of 35 % at 263 K (PLD) and 32 % at 246 K (sol-gel).


1997 ◽  
Vol 494 ◽  
Author(s):  
C. Kwon ◽  
Q. X. Jia ◽  
Y. Fan ◽  
M. F. Hundley ◽  
D. W. Reagor ◽  
...  

ABSTRACTWe report the fabrication of ferromagnet-insulator-ferromagnet junction devices using a ramp-edge geometry based on (La0.7Sr0.3)MnO3 ferromagnetic electrodes and a SrTiO3 insulator. The multilayer thin films were deposited using pulsed laser deposition and the devices were patterned using photolithography and ion milling. As expected from the spin-dependent tunneling, the junction magnetoresistance depends on the relative orientation of the magnetization in the electrodes. The maximum junction magnetoresistance (JMR) of 30 % is observed below 300 Oe at low temperatures (T < 100 K).


1997 ◽  
Vol 81 (8) ◽  
pp. 5759-5759 ◽  
Author(s):  
Wei Zhang ◽  
Ian W. Boyd ◽  
Martin Elliott ◽  
William Herrenden-Harkerand

2006 ◽  
Vol 6 (3) ◽  
pp. 612-617
Author(s):  
Ashutosh Tiwari ◽  
J. Narayan

We report the growth of a new class of superlattice structure, consisting of alternate layers of La0.7Sr0.3MnO3 (LSMO) and ZnO, which exhibits giant magnetoresistance at low fields. These superlattices were fabricated using a novel pulsed-laser deposition technique with a specially designed target assembly. Giant magnetoresistance of >250% has been observed in these structures in current-in-plane configuration on the application of just ∼400 Gauss of magnetic field over the broad temperature range 15–200 K. Observation of giant magnetoresistance at such low magnetic fields is a groundbreaking step in the field of novel magnetic materials and devices.


2011 ◽  
Vol 287-290 ◽  
pp. 2248-2251
Author(s):  
Qian Qian Hua ◽  
Li Sheng Zhang ◽  
Pei Jie Wang

The laser-induced thermoelectric voltage was observed for the first time in praseodymium doped LaMnO3 thin film grown on LaAlO3 single crystal vicinal cut substrates by pulsed laser deposition. The experimental data for La0.5Pr0.5MnO3 showed a good liner relation between the voltage and the laser energy. The result suggested that the anisotropic Seebeck effect were responsible for the voltage signals in colossal magnetoresistance manganites thin film.


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