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Emilia Morosan

Associate Professor in Physics and Astronomy, Chemistry, & Materials Science and Nanomaterials Engineering

Strongly correlated electron systems, heavy fermions, local moment and itinerant electron magnetism, superconductivity, charge density wave transitions.

QUANTUM CRITICALITY IN HEAVY FERMION COMPOUNDS: Phase transitions are driven by the tendency of systems to minimize their energy with respect to extrinsic parameters (pressure, magnetic field etc.). Very often phase transitions occur at finite temperatures, where the thermal fluctuations become smaller than a characteristic energy, in which case the energy is lowered via a symmetry change (broken symmetry) and the nature of the material changes, for example from liquid to solid as water freezes. We are interested in phase transitions that take place at T = 0, known as quantum critical transitions, given that quantum and not thermal fluctuations are now at play. These often occur in a special class of metals known as heavy fermions. We are focusing on the Yb-based heavy fermion compounds, and their properties in the vicinity of the quantum critical point (QCP). Spin fluctuations modify the electron states near a QCP, leading to the breakdown of the Fermi Liquid (FL) theory. We aim at understanding how different control parameters (chemical doping, magnetic field, pressure) affect the non-Fermi liquid (NFL) state.

SUPERCONDUCTIVITY: Despite the success of BCS theory in explaining conventional superconductivity, many questions remain both about conventional and high temperature superconductors. We are particularly interested in answering questions regarding the competition between density waves and superconductivity, both collective electronic states caused by Fermi surface instabilities. In addition, the recent discovery of Fe-based layered superconductors has revitalized the pursuit of high temperature superconductivity. The proximity to a magnetic instability due to the presence of the Fe ions appears key for the occurrence of superconductivity at surprisingly high temperatures, albeit smaller than in the cuprates. We are interested in the design and discovery of new superconducting materials related to these Fe-based compounds, and with improved properties for practical applications. Understanding superconductivity in the vicinity of magnetism and particularly the correlations between crystal structure and superconducting properties is also at the core of our focus on superconducting materials.

ITINERANT ELECTRON MAGNETISM: Magnetic order can occur in at least two classes of compounds: One consists of compounds based on rare earth ions, which have unfilled f-shell electrons acting as localized magnetic moments. Many compounds based on transition metals owe their magnetic properties to the more delocalized d-electrons, and are therefore known as itinerant magnets. Although Stoner theory provides the grounds for understanding the complex magnetism associated with itinerant moments, a unified theory for d-electron magnetism is lacking, particularly due to the limited number of known such compounds. It is our goal to design, discover and synthesize novel itinerant ferromagnetic compounds, and to answer questions regarding the role of spin fluctuations and the quantum criticality in these systems.

REDUCED DIMENSIONAL SYSTEMS AND DENSITY WAVES: Charge density waves (CDWs) are periodic modulations of the electron density in solids. They are collective states that arise due to intrinsic instabilities often present in low dimensional electronic systems. We are interested in studying the competition between CDW transitions and other cooperative electronic phenomena (for example superconductivity) as a function of pressure or chemical doping. These parameters modify the Fermi surface or the electron-phonon coupling, and thus tip the balance in favor of one or the other state as the choice of ground state.

Publications

J. K. Wang, Liang L. Zhao, Q. Yin, G. Kotliar, Moosung Kim, M. C. Aronson  and E. Morosan, “Layered transition metal pnictide SrMnBi2 with metallic blocking layer” Phys. Rev. B 84, 064428 (2011) - Editor’s suggestion

Jian-Xin Zhu, Rong Yu, Hangdong Wang, Liang L. Zhao, M. D. Jones, Jianhui Dai, Elihu Abrahams, E. Morosan, Minghu Fang and Qimiao Si, “Band Narrowing and Mott Localization in Iron Oxychalcogenides La2O2Fe2O(Se,S)2” Phys. Rev. Lett. 104 (2010), 216405

Eteri Svanidze, Emilia Morosan, "Cluster-glass behavior induced by local moment doping in the itinerant feromagnet Sc3.1In" Phys. Rev. B 88, 064412 (2013)

W. Phelan, Michael Kangas, Brenton Drake, Liang L. Zhao, Jiakui K. Wang, John, E. Morosan, Julia Chan, “Crystal Growth, Structure, and Physical Properties of LnCu2(Al,Si)5 (Ln = La and Ce)”, Inorg. Chem. 51, 920 (2012)

K. L. Holman, E. Morosan, P. A. Casey, Lu Li, N. P. Ong, T. Klimczuk, C. Felser and R. J. Cava Crystal structure and physical properties of Mg6Cu16Si7 - type M6Ni16Si7 for M = Mg, Sc, Ti, Nb and Ta.  J. Solid State ChemistrySubmitted

Liang L. Zhao, Stella Kim, Gregory McCandles, P. C. Canfield, Julia Chan and E. Morosan, “Effects of chemical doping and hydrostatic pressure effects on CaFe4As3Phys. Rev. B 84 , 104444 (2011)

Yusuke Nambu, Liang L. Zhao, Emilia Morosan, Kyoo Kim, Gabriel Kotliar, Pawel Zajdel, Mark A. Green, William Ratcliff, Jose A. Rodriguez-Rivera and Collin Broholm, “Incommensurate Magnetism in FeAs Strips: Neutron Scattering from CaFe4As3Phys. Rev. Lett. 106, 037201 (2011)

Su-Yang Xu, Chang Liu, N. Alidoust, D. Qian, M. Neupane, J. D. Denlinger, Y. J. Wang, L. A. Wray, R. J. Cava, H. Lin, A. Marcinkova, E. Morosan, A. Bansil and M. Z. Hasan "Observation of Topological Crystalline Insulator phase in the lead tin chalcogenide Pb1-xSnxTe material class" Nature Commun. 3, 1192 (2012)

Liang L. Zhao, Shan Wu, Jiakui K. Wang, J. P. Hodges, C. Broholm, and E. Morosan "Quasi-two-dimensional non-collinear magnetism in the Mott insulator Sr2F2Fe2OS2" Phys. Rev. B 87 , 020406(R) (2013)

Liang L. Zhao, Shan Wu, Jiakui K. Wang, C. Broholm, and E. Morosan “Quasi-two-dimensional non-collinear magnetism in the Mott insulator Sr2F2Fe2OS2”, Phys. Rev. B. (R) 87, 020406 (2012)

E. Morosan, D. Natelson, Andriy H. Nevidomskyy, Q. Si, “Strongly correlated materials at Rice University”, Advanced Materials (invited) 24, 4896 (2012)

Adam C. Colson, Chih‐Wei Chen, E. Morosan and Kenton H. Whitmire ʺSynthesis of Phase‐Pure Ferromagnetic Fe3P Films from Single‐Source Molecular Precursorsʺ Adv. Functional Mater. 22, 1850 (2012)

W. Adam Phelan, Michael J. Kangas, Gregory T. McCandless, Brenton L. Drake, Neel Haldolaarachchige, Liang L. Zhao, Jiakui K. Wang, Xiaoping Wang, David P. Young, Emilia Morosan, Christina Hoffmann, Julia Y. Chan, “Synthesis, Structure, and Physical Properties of Ln(Cu,Al,Ga)13‐x (Ln = La, Ce, Pr, and Eu) and Eu(Cu,Al)13‐xInorg. Chem. 51, 10193 (2012)

Gregory Morrison, Neel Haldolaarachchige, Chih-Wei Chen, David P. Young, Emilia Morosan, and Julia Y. Chan "Synthesis, Structure, and Properties of Ln(2)Ru(3)Al(15) (Ln = Ce, Gd): Comparison with LnRu(2)Al(10) and CeRu4(Al,Si)(15.58)" Inorg. Chem., 2013, 52 (6), pp 3198–3206

Liang L. Zhao, Michael Mehlman, T. Siegrist and E. Morosan, “Thermodynamic and transport properties of RSn2 (R = Tb-Tm, Lu, Y) single crystals” J. Magn. Magn. Mater. 341, 6 (2013)

A. Marcinkova, J. K. Wang, C. Slavonic, Andriy H. Nevidomskyy, K. F. Kelly, Y. Filinchuk, and E. Morosan "Topological metal behavior in GeBi2Te4 single crystals" Phys. Rev. B 88, 165128 (2013)

Liang L. Zhao, Stefan Lausberg, H. Kim, M. A. Tanatar, Manuel Brando, R. Prozorov, and E. Morosan, “Type I Superconductivity in YbSb2 Single Crystals” Phys. Rev. B 85, 214526 (2012)

E. Svanidze and E. Morosan, “Type‐I superconductivity in ScGa3 and LuGa3 single crystals”, Phys. Rev. B 85, 174514 (2012)

C. Sun, J. Kono, A. Imambekov, and E. Morosan, “Anomalous magneto-optical Kerr hysteresis loops in Fe0.25TaS2”, Phys. Rev. B 84, 224402 (2011)

Liang L. Zhao, Tanghong Yi, James C. Fettinger, Susan M. Kauzlarich and E. Morosan, “Fermi liquid state and enhanced electron correlations in the iron pnictide CaFe4As3” Phys. Rev. B (R) 80, 1 (2009) – Editor’s suggestion

M. D. Vannette, S. Yeninas, E. Morosan, R. J. Cava and R. Prozorov, “Local-moment ferromagnetism and unusual magnetic domains in Fe1/4TaS2 crystals” Phys. Rev. B 80, 024421 (2009)

Tanghong Yi, Peter Klavins, Adam P. Dioguardi, Nicholas J. Curro, Liang L. Zhao, E. Morosan and Susan M. Kauzlarich, “Synthesis and thermal stability studies of CaFe4As3“, Eur. J. of Inorg. Chem. 3920 (2011)

M. S. Kim, M. C. Aronson, L. L. Zhao and E. Morosan, “Thermal transport and the spin density wave gap in CaFe4As3”, Phys. Rev. B 84, 075112 (2011)

Eteri Svanidze and E. Morosan,”Doping-induced quantum phase transition in the itinerant ferromagnet Sc3In” Phys. Rev. Lett. (submitted Aug 2011)

E. Morosan, K. E. Wagner, Liang L. Zhao, Y. Hor, A. J. Williams, J. Tao, Y. Zhu and R. J. Cava, “Multiple electronic transitions and superconductivity in PdxTiSe2” Phys. Rev. B 81 (2010), 094524 - Editor's suggestion

D. Qian, D. Hsieh, L. Wray, Y. Xia, R. J. Cava, E. Morosan, M. Z. Hasan, "Evolution of low-lying states in a doped CDW superconductor CuxTiSe2"Phys. B - Cond. Matter 403 1002

H. Barath, M. Kim, J. F. Karpus, S. L. Cooper, P. Abbamonte, E. Fradkin, E. Morosan, and R. J. Cava, "Quantum and Classical Mode Softening Near the Charge-Density-Wave Superconductor Transition of CuxTiSe2" Phys. Rev. Lett.100 106402

E. Morosan, J. A. Fleitman, Q. Huang, J. W. Lynn, Y. Chen, X. Ke, M. L. Dahlberg, P. Schiffer, C. R. Craley and R. J. Cava, "Structure and magnetic properties of the Ho2Ge2O7 pyrogermanate" Phys. Rev. B 77 224423

K. E. Wagner, E. Morosan, Y. S. Hor, J. Tao, Y. Zhu, T. Sanders, T. M. McQueen, H. W. Zandbergen, A. J. Williams, D.V. West and R. J. Cava, "Tuning the Charge Density Wave and Superconductivity in CuxTaS2" Phys. Rev. B 78 104520

E. Morosan, L. Li, N.P. Ong and R. J. Cava, "Anisotropic properties of the layered superconductor Cu0.07TiSe2" Phys. Rev. B 75 104505

E. Morosan, J. Fleitman, T. Klimczuk and R. J. Cava, "Rich magnetic phase diagram in the Kagome-staircase compound Mn3V2O8" Phys. Rev. B 76 144403

G. Li, W. Z. Hu, D. Qian, D. Hsieh, M. Z. Hasan, E. Morosan, R. J. Cava, and N. L. Wang, "Semimetal to semimetal charge density wave transition in 1T-TiSe2" Phys. Rev. Lett. 99 (2007), 27404

E. Morosan, H. W. Zandbergen, Lu Li, Minhyea Lee, J. G. Checkelsky, M. Heinrich, T. Siegrist, N. P. Ong and R. J. Cava, "Sharp switching of the magnetization in Fe1/4TaS2" Phys. Rev. B 75 104401

K. L. Holman, Q. Huang, T. Klimczuk, K. Trzebiatowski, J. W. G. Bos, E. Morosan, J. W. Lynn and R. J. Cava, "Synthesis and properties of the double perovskites La2NiVO6, La2CoVO6 and La2CoTiO6" J. Solid State Chem. 180 75

J.W.G. Bos, M. Lee, E. Morosan, H.W. Zandbergen, W.L. Lee, N.P. Ong, and R. J. Cava Ferromagnetism below 10 K in Mn – doped BiTe.  Phys. Rev. B, 74 2006: 184429

E. Morosan, S. L. Bud'ko, Y. A. Mozharivskyj and P. C. Canfield, "Magnetic field-induced quantum critical point in YbPtIn and YbPt0.98In single crystals" Phys. Rev. B 73 174432

E. Morosan, H. W. Zandbergen, B. S. Dennis, J. W. G. Bos, Y. Onose, T. Klimczuk, A. P. Ramirez, N. P. Ong and R. J. Cava, "Superconductivity in CuxTiSe2" Nature Phys. 2 544

E. Morosan, S. L. Bud'ko, and P. C. Canfield, "Angular dependent planar metamagnetism in the hexagonal compounds TbPtIn and TmAgGe" Phys. Rev. B 71 14445

S. Bud'ko, E. Morosan, and P. C. Canfield, "Anisotropic Hall effect in single-crystal heavy-fermion YbAgGe" Phys. Rev. B 71 54408

E. Morosan, S. L. Bud'ko, and P. C. Canfield, "Magnetic ordering and effects of crystal electric field anisotropy in the hexagonal compounds RPtIn, R = Y, Gd - Lu", Phys. Rev. B 72 14425

E. Morosan, S. L. Bud’ko, P. C. Canfield, M. S. Torikachvili and A. H. Lacerda Thermodynamic and transport properties of RAgGe (R = Tb – Lu) single crystals.  J. Magn. Magn. Mater., 277 2004: 298

E. Morosan, S. L. Bud?ko, P. C. Canfield, M. S. Torikachvili and A. H. Lacerda, "Thermodynamic and transport properties of RAgGe (R = Tb - Lu) single crystals" J. Magn. Magn. Mater. 277 298

Morosan Lab - Quantum Materials
Morosan Lab

  • B. S. Physics (1999) Univ. Al. I. Cuza, Romania
  • Ph.D. Physics (2005) Iowa State University
  • Department of Chemistry
  • Department of Materials Science and NanoEngineering
  • Condensed Matter Experiment
Email: emorosan@rice.edu
Phone: 713-348-2529
Office: Office: Brockman Hall for Physics, 339