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Full-Text Articles in Physics
Substrate Dependent Buffer-Layer Assisted Growth Of Nanoclusters, Jan Honolka, Violetta Sessi, Jian Zhang, Simon Hertenberger, Axel Enders, Klaus Kern
Substrate Dependent Buffer-Layer Assisted Growth Of Nanoclusters, Jan Honolka, Violetta Sessi, Jian Zhang, Simon Hertenberger, Axel Enders, Klaus Kern
Axel Enders Publications
The role of the substrate on the morphology of nanometer size clusters fabricated by buffer layer assisted growth (BLAG) was studied using scanning tunneling microscopy. Clusters of Fe and Co were deposited on Ag(111), Cu(100), Rh(111), and Pt(111) surfaces using identical BLAG parameters, which are temperature, as well as metal and buffer layer coverage. Semi-hemispherical clusters are found on Ag(111) and Cu(100), while flat monolayer high islands are observed on Rh(111) and Pt(111) due to complete wetting. The results of this study are in agreement with the common notion that BLAG is useful to deposit clusters of virtually any material …
Cobalt Nanoclusters On Metal-Supported Xe Monolayers: Influence Of The Substrate On Cluster Formation Kinetics And Magnetism, V. Sessi, K. Kuhnke, J. Zhang, Jan Honolka, Klaus Kern, Axel Enders, P. Bencok, S. Bornemann, Ján Minár, Hubert Ebert
Cobalt Nanoclusters On Metal-Supported Xe Monolayers: Influence Of The Substrate On Cluster Formation Kinetics And Magnetism, V. Sessi, K. Kuhnke, J. Zhang, Jan Honolka, Klaus Kern, Axel Enders, P. Bencok, S. Bornemann, Ján Minár, Hubert Ebert
Axel Enders Publications
The growth dynamics of submonolayer coverages of cobalt during buffer layer assisted growth on Ag(111) and Pt(111) substrates is investigated by variable temperature scanning tunneling microscopy in the temperature range between 80 and 150 K. It is found that attractive cluster-substrate interactions can govern the cluster formation on the Xe buffer layer if the Xe layer is sufficiently thin. The interpretation of the microscopy results is supported by x-ray magnetic circular dichroism data which monitor the effect of cluster-substrate interactions on the formation of magnetic moments and magnetic anisotropy of Co nanocluster during the different stages of growth. Ab initio …
Cobalt Nanoclusters On Metal-Supported Xe Monolayers: Influence Of The Substrate On Cluster Formation Kinetics And Magnetism, V. Sessi, K. Kuhnke, J. Zhang, Jan Honolka, Klaus Kern, Axel Enders, P. Bencok, S. Bornemann, J. Minár, Hubert Ebert
Cobalt Nanoclusters On Metal-Supported Xe Monolayers: Influence Of The Substrate On Cluster Formation Kinetics And Magnetism, V. Sessi, K. Kuhnke, J. Zhang, Jan Honolka, Klaus Kern, Axel Enders, P. Bencok, S. Bornemann, J. Minár, Hubert Ebert
Axel Enders Publications
The growth dynamics of submonolayer coverages of cobalt during buffer-layer assisted growth on Ag(111) and Pt(111) substrates is investigated by variable temperature scanning tunneling microscopy in the temperature range between 80 and 150 K. It is found that attractive cluster-substrate interactions can govern the cluster formation on the Xe buffer layer if the Xe layer is sufficiently thin. The interpretation of the microscopy results is supported by x-ray magnetic circular dichroism data which monitor the effect of cluster-substrate interactions on the formation of magnetic moments and magnetic anisotropy of Co nanocluster during the different stages of growth. Ab initio calculations …
Magnetic Surface Nanostructures, Axel Enders, Ralph A. Skomski, Jan Honolka
Magnetic Surface Nanostructures, Axel Enders, Ralph A. Skomski, Jan Honolka
Axel Enders Publications
Recent trends in the emerging field of surface-supported magnetic nanostructures are reviewed. Current strategies for nanostructure synthesis are summarized, followed by a predominantly theoretical description of magnetic phenomena in surface magnetic structures and a review of experimental research in this field. Emphasis is on Fe- or Co-based nanostructures in various low-dimensional geometries, which are studied as model systems to explore the effects of dimensionality, atomic coordination, chemical bonds, alloying and, most importantly, interactions with the supporting substrate on the magnetism. This review also includes a discussion of closely related systems, such as 3d element impurities integrated into organic networks, surface-supported …
Magnetic Susceptibility Of Nanoscale Kondo Systems, Ralph Skomski, R. Zhang, Parashu Kharel, Axel Enders, Sy_Hwang Liou, D. J. Sellmyer
Magnetic Susceptibility Of Nanoscale Kondo Systems, Ralph Skomski, R. Zhang, Parashu Kharel, Axel Enders, Sy_Hwang Liou, D. J. Sellmyer
Axel Enders Publications
The mesoscopic Kondo effect in metallic nanoparticles containing a magnetic impurity is investigated by model calculations. A Maxwell–Garnett approach is used to approximately determine the resistivity of doped nanoparticles in a matrix, and the magnetic susceptibility is estimated from the confinement of the conduction electrons. Conductivity measurements of nanoparticles embedded in a matrix are difficult to realize, because metallic matrices distort the Kondo cloud, whereas insulating or semiconducting matrices yield a very weak signal. By comparison, susceptibility measurements do not suffer from these shortcomings. The Kondo effect survives in nanoparticles even if the cluster size is much smaller than the …
Polarized Neutron Reflectometry Study Of The Magnetization Reversal Process In Yba2cu3o7 /La2/3ca1/3mno3 Superlattices Grown On Srtio3 Substrates, J. Hoppler, H. Fritzsche, V. K. Malik, J. Stahn, G. P. Cristiani, H.-U. Habermeier, M. Rössle, Jan Honolka, Axel Enders, C. Bernhard
Polarized Neutron Reflectometry Study Of The Magnetization Reversal Process In Yba2cu3o7 /La2/3ca1/3mno3 Superlattices Grown On Srtio3 Substrates, J. Hoppler, H. Fritzsche, V. K. Malik, J. Stahn, G. P. Cristiani, H.-U. Habermeier, M. Rössle, Jan Honolka, Axel Enders, C. Bernhard
Axel Enders Publications
Using polarized neutron reflectometry we investigated the reversal of the magnetization of a high-Tc superconductor/ferromagnet superlattice that consists of eight bilayers of YBa2Cu3O7(25.6 nm) /La2/3Ca1/3MnO3(25.6 nm) grown on a SrTiO3 substrate. The measurements were performed during a magnetization hysteresis loop at 5 K. We obtained evidence that the reversal in the vicinity of the coercive field proceeds via the switching of micrometer-sized magnetic domains that are considerably larger than the typical domains of La2/3Ca1/3MnO3. Furthermore, these large magnetic domains …
Self-Assembly And Properties Of Nonmetalated Tetraphenyl-Porphyrin On Metal Substrates, Geoffrey Rojas, Xumin Chen, Cameron Bravo, Ji-Hyun Kim, Jae-Sung Kim, Jie Xiao, Peter A. Dowben, Yi Gao, Xiao Cheng Zeng, Wonyoung Choe, Axel Enders
Self-Assembly And Properties Of Nonmetalated Tetraphenyl-Porphyrin On Metal Substrates, Geoffrey Rojas, Xumin Chen, Cameron Bravo, Ji-Hyun Kim, Jae-Sung Kim, Jie Xiao, Peter A. Dowben, Yi Gao, Xiao Cheng Zeng, Wonyoung Choe, Axel Enders
Axel Enders Publications
The structure−electronic structure relationship of nonmetalated meso-tetraphenyl porphyrin (2H-TPP) on the (111) surfaces of Ag, Cu, and Au was studied with a combination of scanning tunneling microscopy, photoelectron spectroscopy, and density functional theory. We observe that the molecules form a 2D network on Ag(111), driven by attractive intermolecular interactions, while the surface migration barriers are comparatively small and the charge transfer to the adsorbed molecules is minimal. This is in contrast to a significant charge transfer observed in 2H-TPP/Cu(111), resulting in repulsive forces between the molecules that prevent molecular adlayer network formation. It is shown that the limiting factor in …