jap banner
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

SECTION LISTING

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

15 May 2003

Volume 93, Issue 10, pp. 5855-8792

Return to All Sections
back to top
RSS Feeds

Anomalous Hall effect of calcium-doped lanthanum cobaltite films

S. A. Baily and M. B. Salamon

J. Appl. Phys. 93, 8316 (2003); http://dx.doi.org/10.1063/1.1540183 (3 pages) | Cited 7 times

Online Publication Date: 9 May 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The Hall resistivity, magnetoresistance, and magnetization of La1−xCaxCoO3 epitaxial films with 0.25⩾x⩾0.4 grown on lanthanum aluminate were measured in fields up to 7 T. The x=1/3 film shows a reentrant metal insulator transition. Below 100 K, the x=1/3 and 0.4 films have significant coercivity which increases with decreasing temperature. At low temperature the Hall resistivity remains large and essentially field independent in these films, except for a sign change at the coercive field that is more abrupt than the switching of the magnetization. A unique magnetoresistance behavior accompanies this effect. These results are discussed in terms of a percolation picture and the mixed spin state model for this system. We propose that the low-temperature Hall effect is caused by spin-polarized carriers scattering off of orbital disorder in the spin-ordered clusters. © 2003 American Institute of Physics.
Show PACS
75.47.Pq Other materials
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
72.25.-b Spin polarized transport
75.70.Ak Magnetic properties of monolayers and thin films
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
72.60.+g Mixed conductivity and conductivity transitions
71.30.+h Metal-insulator transitions and other electronic transitions
75.50.Dd Nonmetallic ferromagnetic materials

Domain nucleation and growth of La0.7Ca0.3MnO3−δ/LaAlO3 films studied by low temperature magnetic force microscopy

M. Liebmann, U. Kaiser, A. Schwarz, R. Wiesendanger, U. H. Pi, T. W. Noh, Z. G. Khim, and D.-W. Kim

J. Appl. Phys. 93, 8319 (2003); http://dx.doi.org/10.1063/1.1555315 (3 pages) | Cited 2 times

Online Publication Date: 9 May 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The field-dependent domain structure of epitaxial La0.7Ca0.3MnO3−δ thin films grown on a LaAlO3(001) substrate has been studied as a function of film thickness (50 and 100 nm) and oxygen content (optimum and deficient) by means of magnetic force microscopy at 5.2 K. The epitaxially grown films show a stress induced out-of-plane anisotropy. All samples exhibit a maze type domain structure at zero field. Domain size and contrast depend on film thickness. The effect of oxygen content could not clearly been determined. Field-dependent measurements were performed by ramping a perpendicular magnetic field of up to 800 mT continuously during imaging. Domain nucleation and growth takes place by discrete reorientation of regions, which have diameters similar to the final domain width. © 2003 American Institute of Physics.
Show PACS
75.70.Ak Magnetic properties of monolayers and thin films
75.70.Kw Domain structure (including magnetic bubbles and vortices)
75.30.Gw Magnetic anisotropy
75.47.Gk Colossal magnetoresistance
75.47.Lx Magnetic oxides
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
75.50.Dd Nonmetallic ferromagnetic materials

Magnetic domain structure and lattice distortions in manganite films under tensile strain

Yeong-Ah Soh, G. Aeppli, C.-Y. Kim, N. D. Mathur, and M. G. Blamire

J. Appl. Phys. 93, 8322 (2003); http://dx.doi.org/10.1063/1.1558716 (3 pages) | Cited 11 times

Online Publication Date: 9 May 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We performed detailed studies of the magnetic domain structure and strain effects in epitaxial La1−xSrxMnO3(001) films grown on SrTiO3(001) bicrystal substrates by combining magnetic force microscopy, x-ray diffraction, and classical magnetometry. We show that, in addition to magnetic domain walls which nucleate at grain boundaries, 180° magnetic domain walls not associated with structural defects form along the 〈100〉 direction. The size of the magnetic domains are of the order of tens of microns with the magnetic easy axes along the 〈100〉 direction in the plane of the film. Spin reorientation occurs at the grain boundaries, which we attribute to the different strain state compared to the grain interior. © 2003 American Institute of Physics.
Show PACS
75.70.Kw Domain structure (including magnetic bubbles and vortices)
68.60.Bs Mechanical and acoustical properties
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
75.70.Ak Magnetic properties of monolayers and thin films
75.30.Ds Spin waves
75.40.Gb Dynamic properties (dynamic susceptibility, spin waves, spin diffusion, dynamic scaling, etc.)
68.37.Rt Magnetic force microscopy (MFM)
61.72.Mm Grain and twin boundaries
75.47.Gk Colossal magnetoresistance
75.47.Lx Magnetic oxides

Slow relaxation of grain boundary resistance in a ferromagnetic manganite

N. Kozlova, K. Dörr, D. Eckert, A. Handstein, Y. Skourski, T. Walter, K.-H. Müller, and L. Schultz

J. Appl. Phys. 93, 8325 (2003); http://dx.doi.org/10.1063/1.1544455 (3 pages) | Cited 4 times

Online Publication Date: 9 May 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The resistance relaxation of a polycrystalline ferromagnetic La0.7Sr0.3MnO3 thin film has been studied. Time-dependent resistance data R(t), recorded after field pulses of 7 and 47 T, respectively, show a pronounced relaxation of approximately logarithmic type for 10 ms<t<20 s and temperatures T<100 K. The resistance relaxation has also been measured in a superconducting quantum interference device magnetometer, yielding similar relaxation rates. An unusual increase of the relaxation rate with decreasing temperature down to 4.2 K is observed. While polycrystalline samples show this type of relaxation, it is absent in an epitaxial film, indicating the origin in the grain boundary regions between misaligned grains. Slow relaxation might be caused by spin glass-like magnetic order at grain boundaries; however, no freezing temperature has been found down to 4.2 K. © 2003 American Institute of Physics.
Show PACS
75.47.Lx Magnetic oxides
61.72.Mm Grain and twin boundaries
75.50.Dd Nonmetallic ferromagnetic materials
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
75.70.Ak Magnetic properties of monolayers and thin films

Phase diagram and Hall effect of the electron doped manganite La1−xCexMnO3

P. Raychaudhuri, C. Mitra, P. D. A. Mann, and S. Wirth

J. Appl. Phys. 93, 8328 (2003); http://dx.doi.org/10.1063/1.1556976 (3 pages) | Cited 26 times

Online Publication Date: 9 May 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the electronic, transport, and magnetic properties of the Ce-doped manganite, La1−xCexMnO3. This material is remarkably similar to the heavily investigated hole doped manganite La1−xCaxMnO3; e.g., both materials show Curie temperatures of TC∼250 K for x=0.3. The main difference which makes the Ce-doped material highly interesting for basic research as well as for possible applications (e.g., in spintronics) is the fact that Ce doping drives the manganese in a mixture of Mn2+ and Mn3+ induced by electron doping. We present conclusive evidence for electron doping by x-ray absorption spectroscopy and Hall measurements on single phase epitaxial thin films. From transport measurements on a series of La1−xCexMnO3, the magnetic phase diagram of La1−xCexMnO3 is established. © 2003 American Institute of Physics.
Show PACS
75.50.Dd Nonmetallic ferromagnetic materials
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.70.Ak Magnetic properties of monolayers and thin films
75.47.Lx Magnetic oxides
75.30.Mb Valence fluctuation, Kondo lattice, and heavy-fermion phenomena
78.70.Dm X-ray absorption spectra
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)

Enhancement of ferromagnetism and metallicity in Ru-doped layered manganite system La1.2Ca1.8Mn2−xRuxO7 (x=0,0.1,0.5,1.0)

Nori Sudhakar, K. P. Rajeev, and A. K. Nigam

J. Appl. Phys. 93, 8331 (2003); http://dx.doi.org/10.1063/1.1556977 (3 pages) | Cited 8 times

Online Publication Date: 9 May 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report here the interesting magnetic and electrical transport properties of Ru-doped two-dimensional manganite system La1.2Ca1.8Mn2−xRuxO7 (x=0,0.1,0.5,1.0). This work aims to investigate the nature of the magnetic phase especially at low temperatures and electrical transport in the light of metal insulator transition exhibited by similar systems. The Ru doping is found to affect the magnetic and electrical properties considerably. The ferromagnetic ordering temperature (Tc) increases from 264 K for x=0 to 285 K for x=0.5 sample. © 2003 American Institute of Physics.
Show PACS
75.50.Dd Nonmetallic ferromagnetic materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
72.15.Nj Collective modes (e.g., in one-dimensional conductors)
72.60.+g Mixed conductivity and conductivity transitions
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)

Magnetic clusters in Nd1−xSrxMnO3 (0.3⩽x⩽0.5): An electron-spin resonance study

S. Angappane, G. Rangarajan, and K. Sethupathi

J. Appl. Phys. 93, 8334 (2003); http://dx.doi.org/10.1063/1.1555316 (3 pages) | Cited 11 times

Online Publication Date: 9 May 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The paramagnetic electron-spin resonance (ESR) linewidth of polycrystalline Nd1−xSrxMnO3 (x=0.3, 0.33, 0.4, and 0.5) increases in a quasilinear manner up to 400 K due to the formation of paramagnetic clusters, which is also confirmed by the observation of an activated behavior of the ESR intensity above TC. Upon cooling, a pair of ferromagnetic resonance lines appear well above the magnetic transition temperature (TC, TN) in all cases. This suggests the presence of ferromagnetic clusters at a temperature T∗>TC. The two-line structure below T∗ is discussed in terms of phase separation and formation of magnetic clusters and their coexistence with a charge-ordered phase for x>0.4. © 2003 American Institute of Physics.
Show PACS
75.50.Dd Nonmetallic ferromagnetic materials
76.50.+g Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance
75.50.Tt Fine-particle systems; nanocrystalline materials
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
76.30.Fc Iron group (3d) ions and impurities (Ti-Cu)
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close