7 Papers
97 Citations
J. Dvorak is an academic researcher from National Center for Electron Microscopy. The author has contributed to research in topics: X-ray absorption spectroscopy & Magnetic circular dichroism. The author has an hindex of 7, co-authored 7 publications.
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Papers
•Journal Article
Determining Exchange Splitting in a Magnetic Semiconductor by Spin-Filter Tunneling
Tiffany S. Santos,Jagadeesh S. Moodera,K. Venkataraman,Ezana Negusse,J. Holroyd,J. Dvorak,M. Lierati,Yves Idzerda,Elke Arenholz +8 more
TL;DR: A large exchange splitting of the conduction band in ultrathin films of the ferromagnetic semiconductor EuO was determined quantitatively, by using EUO as a tunnel barrier and fitting the current-voltage characteristics and temperature dependence to tunneling theory.
Effect of electrode and EuO thickness on EuO-electrode interface in tunneling spin filter
Ezana Negusse,J. Holroyd,M. Liberati,J. Dvorak,Yves Idzerda,Tiffany S. Santos,Jagadeesh S. Moodera,Elke Arenholz +7 more
TL;DR: In this paper, the effect of electrode material and EuO film thickness on the interface between the two was studied by decomposing the x-ray absorption spectroscopy (XAS) spectra of the samples with different electrodes against the reference euO and eu2O3 spectra, the relative fraction of these two species was quantified.
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Comparative x-ray absorption spectroscopy study of Co-doped SnO2 and TiO2
TL;DR: In this paper, x-ray absorption spectroscopy measurements at the cobalt L 2,3 edge and the oxygen K edge of Co-doped SnO2 and Co-Doped TiO2 were performed.
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Chemical Inhomogeneity and Mixed-State Ferromagnetism in Diluted Magnetic Semiconductor Co:TiO2
S. B. Ogale,Darshan C. Kundaliya,S Mehraeen,L. F. Fu,Shixiong Zhang,Alexandre Lussier,J. Dvorak,Nigel D. Browning,Yves Idzerda,Thirumalai Venkatesan +9 more
TL;DR: In this article, a combined window of high-resolution scanning transmission electron microscopy and electron energy-loss spectrometry, X-ray absorption (XAS)/X-ray magnetic circular dichroism (XMCD), and magnetization measurements on epitaxial rutile Co x Ti 1-x O 2 (x = 0-0.06) system (the first discovered oxide-DMS, which continues to be controversial) grown at low temperature (400 °C) under different ambient atmospheres.
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Magnetic characterization of CoFeB∕MgO and CoFe∕MgO interfaces
Ezana Negusse,Alex Lussier,J. Dvorak,Yves Idzerda,S. R. Shinde,Yoshinori Nagamine,S. Furukawa,K. Tsunekawa,David D. Djayaprawira +8 more
TL;DR: In this article, the authors show that the behavior of the magnetic moments located at the CoFe-MgO interface are drastically different from the rest of a CoFe film, whereas the magnetic response of the coFeB-mgO interfacial moments is coherent with the film's bulk.
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