Influence of finite size and image charge screening on the antiferromagnetic ordering of CoO ultrathin films

2020 ◽  
Vol 515 ◽  
pp. 167292
Author(s):  
Sukanta Barman ◽  
Asish K. Kundu ◽  
Krishnakumar S.R. Menon
Keyword(s):  
Ultrathin Films ◽  
Finite Size ◽  
Image Charge ◽  
Charge Screening ◽  
Antiferromagnetic Ordering

scholarly journals Finite-size Kosterlitz-Thouless transition in 2DXY Fe/W(001) ultrathin films

2019 ◽  
Vol 99 (12) ◽  
Author(s):  
J. Atchison ◽  
A. Bhullar ◽  
B. Norman ◽  
D. Venus
Keyword(s):  
Ultrathin Films ◽  
Finite Size

Influence of the Size Effect on Magnetic Susceptibility in Ultrathin Films

2015 ◽  
Vol 233-234 ◽  
pp. 639-642
Author(s):  
Leonid L. Afremov ◽  
Aleksandr A. Petrov
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Magnetic Susceptibility ◽  
Theoretical Analysis ◽  
Ultrathin Films ◽  
Transition Point ◽  
Finite Size ◽  
Phase Transition Point ◽  
Shape Curve ◽  
Good Agreement

The magnetic susceptibility dependence on temperature near phase transition point was investigated by theoretical analysis. It is shown that with decreasing of the film thickness the magnetic susceptibility shape curve becomes more rounded finite-size function, centered about the lowered temperature Tc (L). The obtained results are in good agreement with experimental data.

scholarly journals Image charge screening: A new approach to enhance magnetic ordering temperatures in ultrathin correlated oxide films

2009 ◽  
Vol 79 (17) ◽  
Author(s):  
S. Altieri ◽  
M. Finazzi ◽  
H. H. Hsieh ◽  
M. W. Haverkort ◽  
H.-J. Lin ◽  
...  
Keyword(s):  
Oxide Films ◽  
Magnetic Ordering ◽  
Image Charge ◽  
New Approach ◽  
Charge Screening

Crystallization of Poly(l-lactide) Confined in Ultrathin Films: Competition between Finite Size Effects and Irreversible Chain Adsorption

2014 ◽  
Vol 47 (7) ◽  
pp. 2354-2360 ◽  
Author(s):  
D. E. Martínez-Tong ◽  
B. Vanroy ◽  
M. Wübbenhorst ◽  
A. Nogales ◽  
S. Napolitano
Keyword(s):  
Ultrathin Films ◽  
Size Effects ◽  
Finite Size ◽  
Finite Size Effects

Finite size scaling and universality class in ultrathin films

2004 ◽  
Vol 270 (1-2) ◽  
pp. 119-123 ◽  
Author(s):  
M.S. Amazonas ◽  
J. Cabral Neto ◽  
J. Ricardo de Sousa
Keyword(s):  
Ultrathin Films ◽  
Finite Size ◽  
Universality Class ◽  
Finite Size Scaling ◽  
Size Scaling ◽  
Scaling And Universality

Magnetic Behavior of Ultrathin Films of Pseudomorphic Binary Alloys

1995 ◽  
Vol 400 ◽  
Author(s):  
S.Z. Wu ◽  
F.O. Schumann ◽  
G.J. Mankey ◽  
R.F. Willis
Keyword(s):  
Curie Temperature ◽  
Ultrathin Films ◽  
Scaling Law ◽  
Finite Size ◽  
Magnetic Behavior ◽  
Ferromagnetic Phase ◽  
Ferromagnetic Behavior ◽  
Invar Effect ◽  
Wide Range ◽  
Thickness Measurements

AbstractIn this work we compare the ferromagnetic behavior of ultrathin FexNi(1-x) and CoxNi(1-x) films grown on Cu(100) epitaxially with varying stoichiometry. The thickness regime chosen was 1 to 5 ML over a wide range of alloy composition. Using a finite-size scaling law we proposed for the Curie temperature vs. film thickness measurements, we extrapolate and plot the bulk fee Curie temperature as a function of composition. The results suggest that the growth of these films is pseudomorphic with the films adapting a fee structure and the Cu lattice constant. Besides, the Invar effect is not observed in these ultrathin films of FexNi(1-x) alloys and the magnetic phase of Fe atoms is the low-spin ferromagnetic phase. The CoxNi(1-x) films show the expected monotonic decrease in Tc with increasing Ni content.

FERROMAGNETIC MONOLAYERS

1995 ◽  
Vol 09 (24) ◽  
pp. 3115-3180 ◽  
Author(s):  
HANS-JOACHIM ELMERS
Keyword(s):  
Ultrathin Films ◽  
Size Effects ◽  
Systematic Approach ◽  
Magnetic Phase ◽  
Finite Size ◽  
Theoretical Models ◽  
Experimental Results ◽  
Finite Size Effects ◽  
Low Coverage ◽  
High Degree

The ferromagnetic properties of ultrathin films grown on non-magnetic substrates provide interesting new insights into the physics of magnetism. In this report we review experiments in the very low coverage regime (Θ < 2 atomic layers). The Fe monolayer on W plays an outstanding role, because it forms a ferromagnetic and thermodynamically stable monolayer. Ferromagnetic Fe monolayers on W can be prepared with a high degree of perfection. We therefore focus on ultrathin Fe films on W(110) and W(100) substrates. Experimental results for these in-plane magnetized films, prepared as close as possible to 2-dimensional structures of perfect translational symmetry, are compared with appropriate theoretical models, We also discuss experimental results for the perpendicularly magnetized Co monolayer on Cu(111). The symmetry of the magnetic anisotropy is found to play an important role for the understanding of the magnetic phase transition in 2 dimensions. A new aspect is provided by finite size effects resulting from the morphology of magnetic ultrathin films. Microscopy with atomic resolution allows a systematic approach to the understanding of these finite size effects. Starting from the well-known magnetic properties of the extended Fe monolayer on W(110), we focus on ultrathin Fe films on W(110) deviating from the nearly perfect structure.

Direct imaging of charge transfer

1996 ◽  
Vol 54 ◽  
pp. 680-681
Author(s):  
Yimei Zhu ◽  
J. Tafto
Keyword(s):  
Charge Transfer ◽  
Electron Diffraction ◽  
Scattering Amplitude ◽  
High Temperature Superconductors ◽  
Charge Carriers ◽  
Image Charge ◽  
Net Charge ◽  
Long Time ◽  
Electron Holes ◽  
First Time

The electron holes confined to the CuO2-plane are the charge carriers in high-temperature superconductors, and thus, the distribution of charge plays a key role in determining their superconducting properties. While it has been known for a long time that in principle, electron diffraction at low angles is very sensitive to charge transfer, we, for the first time, show that under a proper TEM imaging condition, it is possible to directly image charge in crystals with a large unit cell. We apply this new way of studying charge distribution to the technologically important Bi2Sr2Ca1Cu2O8+δ superconductors.Charged particles interact with the electrostatic potential, and thus, for small scattering angles, the incident particle sees a nuclei that is screened by the electron cloud. Hence, the scattering amplitude mainly is determined by the net charge of the ion. Comparing with the high Z neutral Bi atom, we note that the scattering amplitude of the hole or an electron is larger at small scattering angles. This is in stark contrast to the displacements which contribute negligibly to the electron diffraction pattern at small angles because of the short g-vectors.

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