Calculated Transport and Magnetic Properties of some Perovskite Metallic Oxides AMO3

1997 ◽  
Vol 494 ◽  
Author(s):  
G. Santi ◽  
T. Jarlborg
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Electronic Structure Calculations ◽  
Structural Deformation ◽  
Fermi Surfaces ◽  
Metallic Oxides ◽  
Self Consistent ◽  
Lmto Method ◽  
Total Energies ◽  
Structure Calculations

ABSTRACTWe study some compounds of the perovskite (or pseudo-cubic perovskite) series AMO3, where M is a transition metal and A is Ca, Sr, or Nd, by LSDA self-consistent electronic structure calculations with the LMTO method. Transport and magnetic properties, as well as Fermi surfaces are calculated. These materials exhibit sharp density of states features in the vicinity of the Fermi level that strongly affect their transport and magnetic properties and make them very sensitive to structural deformation and stoichiometry. Calculated total energies are very close for anti-ferromagnetic and ferromagnetic solutions. This explains qualitatively the magnetoresistive anomalies shown by this family of compounds.

Magnetic Properties of Co Nanoparticles: Role of the Coexistence of Different Geometrical Phases

2008 ◽  
Vol 8 (12) ◽  
pp. 6497-6503
Author(s):  
J. M. Montejano-Carrizales ◽  
R. A. Guirado-López
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Electronic Structure Calculations ◽  
Magnetic Anisotropy Energy ◽  
Self Consistent ◽  
Co Nanoparticles ◽  
Spin Moments ◽  
Structure Calculations ◽  
Size And Structure

Following the experimental results of Respaud et al. [Phys. Rev. B 57, 2925 (1998)] we report self-consistent electronic structure calculations in order to analyze the magnetic properties of Co nanoparticles in which a coexistence of bcc and compact (fcc) phases are present within the particles. In all cases, the local spin moments S(i) are found to be saturated (∼1.7 μB) while, in contrast, the local orbital moments L(i) and the magnetic anisotropy energy (MAE) are found to be very sensitive to the size and structure of the systems. Interestingly, we obtain considerably enhanced values for L(i) at the internal bcc/fcc interfaces which can be even larger than at surfaces sites and, in addition, we found that by varying the fraction of bcc and fcc phases within the particles, several reorientations of the magnetization can be induced, a result that could open new possibilities to tune the MAE of magnetic nanoparticles.

Effect of Boron and Hydrogen on the Electronic Structure of Ni3Al

1993 ◽  
Vol 319 ◽  
Author(s):  
N. Kioussis ◽  
H. Watanabe ◽  
R.G. Hemker ◽  
W. Gourdin ◽  
A. Gonis ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Charge Density ◽  
First Principles ◽  
Electronic Structure Calculations ◽  
Interstitial Site ◽  
Octahedral Interstitial Site ◽  
Interstitial Region ◽  
Ordered Intermetallic ◽  
Lmto Method ◽  
Structure Calculations

AbstractUsing first-principles electronic structure calculations based on the Linear-Muffin-Tin Orbital (LMTO) method, we have investigated the effects of interstitial boron and hydrogen on the electronic structure of the L12 ordered intermetallic Ni3A1. When it occupies an octahedral interstitial site entirely coordinated by six Ni atoms, we find that boron enhances the charge distribution found in the strongly-bound “pure” Ni3AI crystal: Charge is depleted at Ni and Al sites and enhanced in interstitial region. Substitution of Al atoms for two of the Ni atoms coordinating the boron, however, reduces the interstitial charge density between certain atomic planes. In contrast to boron, hydrogen appears to deplete the interstitial charge, even when fully coordinated by Ni atoms. We suggest that these results are broadly consistent with the notion of boron as a cohesion enhancer and hydrogen as an embrittler.

scholarly journals Nanocrystals of CuCr2S4−xSex chalcospinels with tunable magnetic properties

2016 ◽  
Vol 4 (16) ◽  
pp. 3628-3639 ◽  
Author(s):  
Karthik Ramasamy ◽  
Hunter Sims ◽  
Sahar Keshavarz ◽  
Nariman Naghibolashrafi ◽  
Arunava Gupta
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Composition Range ◽  
Electronic Structure Calculations ◽  
Entire Composition Range ◽  
Half Metallic ◽  
Reduced Dimensions ◽  
Structure Calculations

Nanocrystals of magnetic chalcospinels CuCr2S4−xSex (0 ≤ x ≤ 4) have been synthesized over the entire composition range and their magnetic properties investigated. Electronic structure calculations predict metallic characteristics in the bulk and “half-metallic” at reduced dimensions.

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