Emmy Noether Group at the MPI CPfS

Helge Rosner's Homepage

Emmy Noether page

Deepa Kasinathan
 Max-Planck Institute for Chemical Physics of Solids
Nöthnitzer Str. 40
01187 Dresden, Germany
Phone:  +49 351 4646 4221
Fax:  +49 351 4646 4602
E-mail: Deepa.Kasinathan@cpfs.mpg.de
Deepa Kasinathan
Personal background

1999   Undergraduate degree (B.Sc.) in Physics from the South Indian Education Society (S.I.E.S.), University of Mumbai, India.

2001   Masters degree (M.Sc.) in Physics from the Indian Institute of Technology (IIT), Mumbai, India. Thesis work with Prof. Indra Dasgupta. Titel: "First Principles Study of Complex Crystalline Solids" (Emphasis was in understanding the electronic structure andthermoelectric properties of Narrow-gap materials FeVSb, FeNbSb and Chevrel phases.)

2006   Ph.D in Physics from University of California, Davis, U.S.A. with Prof. Warren. E. Pickett. Thesis titel: "Computational Study of Materials Under Pressure" (Systems considered where CoN, MnO-a Mott insulator and Li-a superconductor under pressre)

Since Sept 2006   Post-doctoral researcher in the Emmy Noether Group headed by Dr. Helge Rosner at the Max-Planck Institute for Chemical Physics of Solids (MPI CPfS), Dresden, Germany.

Scientific research topic

Electronic structure, magnetic and superconducting properties of crystalline solids
Abstract of scientific research topic

Many spin 1/2 transition metal oxides and halides have a 4+2 coordination of anions around them. This creates an octahedral crystal field which in turn splits the five d orbitals into low lying triplets and a higher lying doublet. There needs to be an additional splitting of the higher lying doublet together with strong correlations to drive these systems to a spin 1/2 insulator. Many transition metal oxides and halides undergo a distortion (i.e. elongation of the octahedra) to induce a splitting of the eg orbitals, with the antibonding orbital of dx2-y2 symmetry carrying the moment. Interestingly there are systems which choose not to distort in this way but show a strong competition between different orbitally ordered ground states. From these small energy differences between different orbital occupations the strong correlations can select several unusual orbital pattern. We are interested in finding the correct orbital-order pattern using DFT calculations.

Another topic of interest is the new family of Fe pnictide superconductors. In particular the AFe2As2 (A = Sr, Ba, Ca, Eu) systems. We use DFT to understand the electronic structure of these systems.

Electronic structure, lattice dynamics and the thermoelectric power of Clathrates.

Publications
No
Author(s)
Title
 
25
W. Schnelle, A. Leithe-Jasper, R. Gumeniuk, U. Brukhardt, D. Kasinathan, and H. Rosner Chemical strain and superconductivity in the series SrFe2-xRuxAs2 (0 ≤ x ≤ 2) , Phys. Rev. B, vol. 79, 214516, 2009. download (368 kB, PDF)
 
24
C. F. Miclea, M. Nicklas, H.S. Jeevan, D. Kasinathan, Z. Hossain, H. Rosner, P. Gegenwart, C. Geibel, F. Steglich Evidence for a reentrant superconducting state in EuFe2As2 under pressure, Phys. Rev. B, vol. 79, 212509, 2009. download (136 kB, PDF)
 
23
H. Rosner, M. Schmitt, D. Kasinathan, A. Ormeci, J. Richter, S. -L. Drechsler, and M. D. Johannes Comment on \"Electronic structure of spin-1/2 Heisenberg antiferromagnetic systems: Ba2Cu(PO4)2 and Sr2Cu(PO4)2\", Phys. Rev. B, vol. 79, 127101, 2009. download (92 kB, PDF)
 
22
D. Kasinathan, A. Ormeci, K. Koch, U. Burkhardt, W. Schnelle, A. Leithe-Jasper, and H. Rosner AFe2As2 (A = Ca, Sr, Ba, Eu) and SrFe2-xTMxAs2 (TM = Mn, Co, Ni): crystal structure, charge doping, magnetism and superconductivity, New J. Phys., vol. 11, 025023, 2009. download (2 MB, PDF)
 
21
A. Jesche, N. Caroca-Canales, H. Rosner, H. Borrmann, A. Ormeci, D. Kasinathan, H. H. Klauss, H. Luetkens, R. Khasanov, A. Amato, A. Hoser, K. Kaneko, C. Krellner, and C. Geibel Strong coupling between magnetic and structural order parameters in SrFe2As2, Phys. Rev. B, vol. 78, 180504, 2008. download (286 kB, PDF)
 
20
M. Kumar, M. Nicklas, A. Jesche, N. Caroca-Canales, M. Schmitt, M. Hanfland, D. Kasinathan, U. Schwarz, H. Rosner, and C. Geibel Effect of pressure on the magnetostructural transition in SrFe2As2, Phys. Rev. B, vol. 78, 184516, 2008. download (305 kB, PDF)
 
19
H. S. Jeevan, Z. Hossain, D. Kasinathan, H. Rosner, C. Geibel, and P. Gegenwart High-temperature superconductivity in Eu0.5K0.5Fe2As2, Phys. Rev. B, vol. 78, 092406, 2008. download (229 kB, PDF)
 
18
H. S. Jeevan, Z. Hossain, D. Kasinathan, H. Rosner, C. Geibel, and P. Gegenwart Electrical resistivity and specific heat of single-crystalline EuFe2As2: A magnetic homologue of SrFe2As2, Phys. Rev. B, vol. 78, 052502, 2008. download (217 kB, PDF)
 
17
D. Kasinathan, K. Koepernik,and H. Rosner Quasi-one-dimensional magnetism driven by unusual orbital ordering in CuSb2O6, Phys. Rev. Lett., vol. 100, 237202, 2008. download (354 kB, PDF)
 
16
R. Nath, D. Kasinathan, H. Rosner, M. Baenitz, and C. Geibel Electronic and magnetic properties of K2CuP2O7: A model S=1/2 Heisenberg chain system, Phys. Rev. B, vol. 77, 134451, 2008. download (483 kB, PDF)
 
15
D. Kasinathan, K. Koepernik, U. Nitzsche, H. Rosner Ferromagnetism induced by orbital order in the charge-transfer insulator Cs2AgF4: An electronic structure study, Phys. Rev. Lett., vol. 99, 247210, 2007. download (519 kB, PDF)
 
14
D. Kasinathan, K. Koepernik, J. Kunes, H. Rosner and W. E. Pickett Origin of strong coupling in lithium under pressure, Physica C, vol. 460-62, 133, 2007. download (305 kB, PDF)
 
13
D.J. Singh, and D. Kasinathan Thermoelectric properties of NaxCoO2 and prospects for other oxide thermoelectrics, J. Electronic Materials, vol. 36, 736, 2007. download (212 kB, PDF)
 
12
D. Kasinathan, K. Koepernik, W. E. Pickett Pressure-driven magnetic moment collapse in the ground state of MnO, New Journal of Phys., vol. 9, 235, 2007. download (644 kB, PDF)
 
11
D.J. Singh, G. B. Wilson-Short, D. Kasinathan, M. Suewattana, and M. Fornari Electronic structure and disorder in Na(x)CoO2 and SrRh2O4, Solid State Sciences, vol. 9, 604, 2007. download (424 kB, PDF)  Sp. Iss. SI 1st International Symposium on Structure-Property Relationships in Solid State Materials Bordeaux, FRANCE, JUN 27-30, 2006 
 
10
R. C. Rai, J. Cao, S. Brown, J. L. Musfeldt, D. Kasinathan, D. J. Singh, G. Lawes, N. Rogado, R. J. Cava, and X. Wei Optical properties and magnetic-field-induced phase transitions in the ferroelectric state of Ni3V2O8: Experiments and first-principles calculations, Phys. Rev. B, vol. 74, 235101, 2006. download (1 MB, PDF)
 
9
D. Kasinathan, and D. J. Singh Electronic structure of Cr-doped SrRuO3: Supercell calculations, Phys. Rev. B, vol. 74, 195106, 2006. download (283 kB, PDF)
 
8
D. Kasinathan, J. Kunes, K. Koepernik, Cristian V. Diaconu, Richard L. Martin, Inout Prodan, Gustavo E. Scuseria, Nicola Spaldin, L. Petit, T. C. Schulthess, and W. E. Pickett Mott Transition of MnO under Pressure: Comparison of Correlated band Theories , Phys. Rev. B, vol. 74, 195110, 2006. download (951 kB, PDF)
 
7
D. Kasinathan, J. Kunes, A. Lazicki, H. Rosner, C.-S. Yoo, R. T. Scalettar, and W. E. Pickett Superconductivity and lattice instability in compressed lithium from fermi surface hot spots, Phys. Rev. Lett., vol. 96, 047004, 2006. download (481 kB, PDF)
 
6
B. R. Maddox, C.S. Yoo, D. Kasinathan, W. E. Pickett, and R. T. Scalettar High-pressure structure of half-metallic CrO2 , Phys. Rev. B, vol. 73, 144111, 2006. download (282 kB, PDF)
 
5
D. Kasinathan, A. B. Kyker and D. J. Singh Origin of ferromagnetism in Cs2AgF4: The importance of Ag-F covalency, Phys. Rev. B, vol. 73, 214420, 2006. download (365 kB, PDF)
 
4
D.J. Singh, and D. Kasinathan Destruction of the small fermi surfaces in NaxCoO2 by disorder, Phys. Rev. Lett., vol. 97, 016404, 2006. download (487 kB, PDF)
 
3
D. Kasinathan, K. W. Lee, and W. E. Pickett On heavy carbon doping of MgB2, Physica C, vol. 424, 116, 2005. download (336 kB, PDF)
 
2
A. V. Poogrebnyakov, J. M. Redwing, S. Raghavan, V. Vaithyanathan, D. G. Schlom, S. Y. Xu, Q. Li, D. A. Tenne, A. Soukiassian, X. X. Xi, M. D. Johannes, D. Kasinathan, W. E. Pickett, J. S. Wu, and J. C. H. Spence Enhancement of the superconducting transition temperature of MgB2 by a strain-induced bond-stretching mode softening, Phys. Rev. Lett., vol. 93, 147006, 2004. download (376 kB, PDF)
 
1
J. Kunes, H. Rosner, D. Kasinathan, C. O. Rodriguez, and W. E. Pickett Theory of orbital moment collapse under pressure in FeI2, Phys. Rev. B, vol. 68, 115101, 2003. download (553 kB, PDF)
 
In preparation

  1. Stefan Hoffmann, Deepa Kasinathan, and Thomas F. Faessler
    Single Crystals of Rb4C60 : Synthesis and Structure Determination
    In preparation

  2. C. P. Sebastian, Deepa Kasinathan, Yu. Prots, W. Schnelle, U. Brukhardt, H. Rosner and Yu. Grin
    Synthesis and Properties of EuLiGe2 and YbLiGe2
    In Preparation
Invited Talks

  1. Orbital Order is low dimensional spin-1/2 systems
    First Goettingen-India Physics Workshop on Frontiers in Concensed Matter and Complex systems
    University of Goettingen, Goettingen
    November 3-6 2009.

  2. Novel magnetism in Cs2AgF4 and CuSb2O6 via Orbital Ordering.
    Center for Computational Materials Science, Naval Research Laboratory, Washington D.C. U.S.A.
    October 4th 2007.

  3. Novel magnetism in Cs2AgF4 and CuSb2O6 via Orbital Ordering.
    Condensed matter physics and materials science dept., Brookhaven National Lab, Upton, New York. U.S.A.
    October 1st 2007.

  4. Novel magnetism in Cs2AgF4 and CuSb2O6 via Orbital Ordering.
    Crystallography Seminar, Department of Geo und umweltwissenschaften, Ludwig Maximilians University Munich, Germany.
    June 1st 2007.

  5. Origin of Strong Coupling in Lithium under pressure.
    M2S-HTSC-VIII Conference, Dresden, Germany.
    July 2006.

  6. Pressure driven Nonmagnetic to Ferromagnetic transition in CoN.
    Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
    November 2004.

  7. Pressure driven Nonmagnetic to Ferromagnetic transition in CoN.
    Dept. of Magnetism and Superconductivity, Institute of Physics, Prague, Czech Republic.
    October 2004.
Contributed Talks

  1. Frustrated chain magnetism from the interplay of water induced crystal field splitting and correlation in KTi(SO4)2.H2O
    DFT meets Solid State Chemistry & 8th Tutorial Hands-on-FPLO
    Leibniz Institute for Solid State and Materials Research Dresden
    October 25-29, 2009

  2. Electronic structure and exchange coupling of a frustrated S=1/2 pyrochlore Hg2Cu2F6S
    DPG-Dresden, Germany
    March 2009

  3. Orbital Order in low dimensional spin 1/2 systems.
    Workshop DFT meets Experiment & 7th Tutorial Hands-on-FPLO
    IFW Dresden, Germany
    August 25-28, 2008

  4. Orbital Ordering in Spin 1/2 Systems.
    16th International Conference on Solid Compounds of Transition Elements
    Dresden, Germany
    July 26-31, 2008

  5. KTi(SO4)2.H2O - a possible candidate for a new spin-Peierls system.
    DPG-Berlin, Germany & APS-New Orleans, U.S.A.
    February & March 2008

  6. Orbital Ordering in Cs2AgF4 - an electronic structure study.
    Dept. of Physics, Indian Institute of Technology - Bombay, India
    January 2008

  7. Orbital Ordering in Cs2AgF4 - an electronic structure study.
    DPG-Regensburg, Germany & APS-Denver, U.S.A.
    March 2007

  8. Quasi one-dimensional magnetism driven by unusual orbital ordering in CuSb2O6.
    APS-Denver, U.S.A.
    March 2007

  9. LDA+U Picture of the Moment and Volume Collapse under pressure in MnO.
    DPG-Dresden, Germany
    March 2006.

  10. Superconductivity and Lattice Instability in Compressed Lithium from Fermi Surface Hot Spots.
    APS-Baltimore, U.S.A.
    March 2006.

  11. Superconductivity and Lattice Instability in Compressed Lithium from Fermi Surface Hot Spots.
    Oak Ridge Nationa Lab, Tennessee, U.S.A.
    February 2006.

  12. Moment Collapse of MnO under pressure.
    ESESRF/PCSCS - CMSN coordination meeting, Chicago, U.S.A.
    October 15-16 2005.

  13. Moment and Volume Collapse under Pressure in MnO: Theory vs Experiment
    MMM (Magnetism and Magnetic Materials) San Jose, U.S.A.
    October 2005.

  14. High Pressure Transitions in 4f Metals and in Mott Insulating MnO. (With B. Maddox)
    SSAAP Symposium, Las Vegas, U.S.A.
    August 2005.

  15. CoN - an example for open structures in FPLO.
    FPLO workshop, IFW-Dresden, Germany
    March/April 2005.

  16. Supercell and Virtual crystal approximation : On Heavy Carbon Doping of MgB2.
    Workshop for High-Field Intermetallic Superconductors, A satellite meeting at APS-Los Angeles, U.S.A.
    March 2005.

  17. LDA+U Picture of the Moment Collapse under Pressure in MnO.
    APS-Los Angeles, U.S.A.
    March 2005.

  18. Paramagnetic-to-Ferromagnetic Transition in Con Under Pressure.
    APS-Montreal, Canada
    March 2004.

  19. Effect of Heavy Carbon Doping of MgB2.
    APS-Austin, U.S.A.
    March 2003.
Posters

  1. Frustrated chain magnetism from interplay of water induced crystal field splitting and correlation in KTi(SO4)2.H2O ECSSC XII - XIIth European conference on Solid State Chemistry
    Muenster, Germany
    20 - 23 September 2009

  2. Competing interactions in low-dimensional spin 1/2 systems
    KKR and Spectroscopy -- Hands-on Course
    Dept. of Chemistry and Biochemistry, Ludwig Maximilians University Munich, Germany.
    24 - 26 June 2009

  3. Relation of crystal structure, magnetism and charge doping in AFe2As2 (A = Sr, Ba, Eu, Ca) - A computational study
    International Workshop "Physics and Chemistry of FeAs-based Superconductors
    Leibniz Institute for Solid State and Materials Research, Dresden, Germany
    27 - 29 October 2008.

  4. Quasi one-dimensional magnetism driven by unusual orbital ordering in CuSb2O6.
    6th Workshop on Orbital Physics and Novel Phenomena in Transition Metal Oxides
    Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
    10th and 11th of October, 2007.
    download

  5. Pressure driven nonmagnetic to ferromagnetic transition in CoN.
    SSAAP Symposium, UNLV-Las Vegas, U.S.A.
    August 2005.

  6. MnO Moment Collapse: LDA+U Study.
    CMSN coordination meeting, OakRidge, Tennessee, U.S.A.
    October 2004.

  7. Electronic Structure Analysis of FeI2.
    ES2002-Berkeley, U.S.A. Annual Workshop on recent developments in Electronic structure methods
    June 2002

  8. Electronic Structure of half-Heusler Compounds: Narrow-gap thermoelectric materials. (with B. R. K. Nanda and I. Dasgupta)
    DAE Symposium on Solid State Physics, Bhabha Atomic research Center (BARC), Mumbai, India
    November 2001
    download