I joined the Superconductivity and Magnetism Group at Warwick as a Postdoctoral Research Fellow in January 2017 as a part of The Skyrmion Project, where I work with Professor Geetha Balakrishnan.
I completed a Ph.D. in Chemistry at Durham University in 2017 under the supervision of Professor Andrew Beeby. The family of materials I discovered during my Ph.D. work and as post graduate researcher at Jožef Stefan Institute are strongly correlated systems exhibiting a variety of magnetic properties, spanning antiferromagnetism, ferromagnetism, canted-antiferromagnetismm, low-dimensional magnetism and superconductivity. I have performed the characterisation of the obtained novel organic magnets by laboratory- and synchrotron-based (ESRF) x-ray diffraction (also following structural phase transitions and negative thermal expansions), SQUID magnetometry at ambient and hydrostatic pressure, Raman and muon spectroscopy (ISIS). Some of the results are gathered in my thesis and in the publications listed below.
My current research topic involves the synthesis and characterisation of Skyrmion hosting materials. By utilising chemical vapour transport method I have successfully grown single crystals of Cu2OSeO3, Zn-substituted Cu2OSeO3 and the family of GaV4S(8-y)Se(y) (y ranges between 0.5 and 7.5), hosting both Bloch and Néel types of Skrmions. The Bridgman and modified Bridgman techniques were used for growth the single crystal grains of (Mn0.5Ni0.5)65Ga35, Mn1.4Pt0.9Pd0.1Sn and Co(10-x)Zn(10-y)Mn(x+y) intermetallic compounds hosting ‘biskyrmions’, antiskyrmions and Bloch type Skyrmions respectively. The single crystals of Gd2PdSi3, where the frustration is the driving force for skyrmion lattice formation instead of DMI, were grown by the optical floating zone method. The detailed structural characterisation of these materials was achieved by laboratory and synchrotron based single crystal and powder diffraction (Diamond), including anomalous X-ray scattering, along with powder (ILL) and single crystal (ISIS) neutron diffraction. The magnetic properties were investigated by DC- and AC-SQUID magnetometry. I have used Olex2, Jana2006, TOPAS-Academic V6 and Expo2014 to analyse the obtained data.
• K. J. A. Franke, B. M. Huddart, T. J. Hicken, F. Xiao, S. J. Blundell, F. L. Pratt, M. Crisanti, J. Barker, S. J. Clark, A. Štefančič, M. Ciomaga Hatnean, G. Balakrishnan, and T. Lancaster, "Magnetic phases of skyrmion-hosting GaV4S8−ySey (y=0,2,4,8) probed with muon spectroscopy", Accepted for publication in Physical Review B (August 2018).
• A. Štefančič, G. Klupp, T. Knaflič, D. S. Yufit, G. Tavčar, A. Potočnik, A. Beeby and D. Arčon, “Triphenylide-Based Molecular Solid—A New Candidate for a Quantum Spin-Liquid Compound”, The Journal of Physical Chemistry C 121 (27), 14864-14871 (2017).
• Y. Takabayashi, M. Menelaou, H. Tamura, N. Takemori, T. Koretsune, A. Štefančič, G. Klupp, A. J. C. Buurma, Y. Nomura, R. Arita, D. Arčon, M. J. Rosseinsky and K. Prassides, “π-electron S = ½ quantum spin-liquid state in an ionic polyaromatic hydrocarbon”, Nature Chemistry 9, 635-643 (2017).
• B. Alič, A. Štefančič and G. Tavčar, “Small molecule activation: SbF3 auto-ionization supported by transfer and mesoionic NHC rearrangement”, Dalton Transactions 46, 3338 (2017).
• A. Štefančič, D. Primc, G. Tavčar and T. Skapin, “Direct solvothermal preparation of nanostructured fluoride aerogels based on AlF3”, Dalton Transactions 44, 20609 (2015).
• A. Štefančič, S.H. Moody, T.J. Hicken, T.M. Birch, G. Balakrishnan, S.A. Barnett, M. Crisanti, J.S.O. Evans, S.J.R. Holt, K.J.A. Franke, P.D. Hatton, B.M. Huddart, M.R. Lees, F.L. Pratt, C.C. Tang, M.N. Wilson, F. Xiao, and T. Lancaster, “Origin of skyrmion lattice phase splitting in Zn-substituted Cu2OSeO3”
Department of Physics
University of Warwick
Coventry CV4 7AL
+44 (0)2476 574755
A dot Stefancic at warwick dot ac dot uk