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    The Effect of Pressure on the Coexistence of Superconductivity and Magnetism in RuSr2GdCu2O8 and RuSr2Gd1.4Ce0.6Cu2O10-δ

    , Ph.D. Dissertation Sharif University of Technology Fallahi, Saeed (Author) ; Akhavan, Mohammad (Supervisor)
    The coexistence of long-range magnetic order and superconductivity in the ruthenocuprate families, Ru1212 and Ru1222 has been studied both theoretically and experimentally. Historically these two different phases are incompatible with each other and in the most previous research reported on the coexistence of these phases, there have been observed separated magnetic and superconducting phases. However in the ruthenocuprate families, there is a single phase with both magnetic and superconducting phase which coexist with each other. It has been determined that superconductivity arises in CuO2 planes, and magnetic orders occur in RuO2. From experimental point of view, we have investigated the... 

    The formation and dissociation energy of vacancies in cementite: A first-principles study

    , Article Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms ; Volume 502 , 2021 , Pages 157-163 ; 0168583X (ISSN) Mehrdad Zamzamian, S ; Amirhossein Feghhi, S ; Samadfam, M ; Sharif University of Technology
    Elsevier B.V  2021
    Because of the possibility of various types of vacancies in cementite due to its crystalline structure, the focus of this paper was only on vacancies. In this regard, the formation energies of single, two, three and four vacancies of over than 120 different cases were calculated using first-principles method. For the case of single vacancy, the results were in three values of ~1.63, 1.39 and 0.78 eV according to iron vacancies at general positions, iron vacancies located on mirror planes and carbon vacancies in the interstitial positions, respectively. The results for the case of two, three and four vacancies were between from 2.10 to 3.34 eV, from 3.92 to 5.10 eV and from 4.77 to 6.33 eV,...