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Synthesis, structural and physical investigations of novel superconductors and III-V ternary nitrides

English title Synthesis, structural and physical investigations of novel superconductors and III-V ternary nitrides
Applicant Karpinski Janusz
Number 134994
Funding scheme Project funding (Div. I-III)
Research institution Laboratorium für Festkörperphysik ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Condensed Matter Physics
Start/End 01.07.2011 - 30.06.2012
Approved amount 128'986.00
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All Disciplines (2)

Discipline
Condensed Matter Physics
Inorganic Chemistry

Keywords (4)

Superconductor; Single crystals; High-pressure; Iron-arsenide-superconductors

Lay Summary (English)

Lead
Lay summary

Our aims are synthesis and investigations of structural and physical properties of single crystals and polycrystalline samples of strongly anisotropic compounds of high temperature superconductors, including novel superconductors, FeAs based and related compounds. The interplay between crystal-chemical, structural and electronic properties is a central aspect of modern material based condensed matter physics. The study of the influence of chemical substitutions on the superconducting properties is also the aim of the project. By substituting a small amount of foreign elements in the structure one can vary the electron count, create defects or modify the electronic structure leading to an increase of the upper critical field Hc2, critical current or critical temperature and variation of other superconducting parameters. Both chemical and structural subtleties can play a decisive role, and require a thorough and systematic study.

In the synthesis of superconducting materials high pressure methods frequently led to discovery of new superconductors or to obtaining materials with much better properties than those obtained with ambient or low pressure methods. Many most important high Tc superconductors have been synthesized under high pressure as single crystals or as polycrystalline samples.

In the case of Fe-based superconductors LnFeAs(O,F) (Ln=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy) high pressure stabilizes the superconducting phase at higher temperature than in quartz ampoule technique and therefore allows using higher temperatures for the single crystal growth. This is important for increasing the solubility of components for more efficient crystal growth. High pressure stabilizes oxygen deficient superconducting LnFeAsO1-x. In the case of polycrystalline samples high pressure leads to strongly sintered samples with better intergrain connections. The application of high pressure for volatile components prevents evaporation and losses of components.

 Our aims are to grow single crystals and to synthesize polycrystalline samples of pnictides superconductors for investigations of structural and anisotropic physical properties. We will also perform systematic search for new superconductors. In addition to our own investigations of the material, we also collaborate with many laboratories, both in Switzerland and around the world.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
High pressure in the synthesis and crystal growth of superconductors and III-N semiconductors
Karpinski J (2012), High pressure in the synthesis and crystal growth of superconductors and III-N semiconductors, in PHILOSOPHICAL MAGAZINE, 92(19-21), 2662-2685.
Point-Contact Andreev-Reflection Spectroscopy in Fe-Based Superconductors: Multigap Superconductivity and Strong Electron-Boson Interaction
Tortello M, Daghero D, Ummarino GA, Stepanov VA, Zhigadlo ND, Karpinski J, Jiang J, Gonnelli RS (2012), Point-Contact Andreev-Reflection Spectroscopy in Fe-Based Superconductors: Multigap Superconductivity and Strong Electron-Boson Interaction, in JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM, 25(5), 1297-1301.
Point-contact spectroscopy in Co-doped CaFe2As2: nodal superconductivity and topological Fermi surface transition
Gonnelli RS, Tortello M, Daghero D, Kremer RK, Bukowski Z, Zhigadlo ND, Karpinski J (2012), Point-contact spectroscopy in Co-doped CaFe2As2: nodal superconductivity and topological Fermi surface transition, in SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 25(6), 65007-65017.
Bulk Electronic Structure of Superconducting LaRu2P2 Single Crystals Measured by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy
Razzoli E, Kobayashi M, Strocov VN, Delley B, Bukowski Z, Karpinski J, Plumb NC, Radovic M, Chang J, Schmitt T, Patthey L, Mesot J, Shi M (2012), Bulk Electronic Structure of Superconducting LaRu2P2 Single Crystals Measured by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy, in PHYSICAL REVIEW LETTERS, 108(25), 257005-257009.
Interplay Between Spin Density Wave and Superconductivity in '122' Iron Pnictides: Fe-57 Mossbauer Study
Blachowski A, Ruebenbauer K, Zukrowski J, Bukowski Z, Matusiak M, Karpinski J (2012), Interplay Between Spin Density Wave and Superconductivity in '122' Iron Pnictides: Fe-57 Mossbauer Study, in ACTA PHYSICA POLONICA A, 121(4), 726-729.
Observation of Well-Ordered Metastable Vortex Lattice Phases in Superconducting MgB2 Using Small-Angle Neutron Scattering
Das P, Rastovski C, O'Brien TR, Schlesinger KJ, Dewhurst CD, DeBeer-Schmitt L, Zhigadlo ND, Karpinski J, Eskildsen MR (2012), Observation of Well-Ordered Metastable Vortex Lattice Phases in Superconducting MgB2 Using Small-Angle Neutron Scattering, in PHYSICAL REVIEW LETTERS, 108(16), 167001-167005.
Imaging flux vortices in MgB2 using transmission electron microscopy
Loudon JC, Bowell CJ, Zhigadlo ND, Karpinski J, Midgley PA (2012), Imaging flux vortices in MgB2 using transmission electron microscopy, in PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 474, 18-20.
Scanning Hall probe microscopy of unconventional vortex patterns in the two-gap MgB2 superconductor
Gutierrez J, Raes B, Silhanek AV, Li LJ, Zhigadlo ND, Karpinski J, Tempere J, Moshchalkov VV (2012), Scanning Hall probe microscopy of unconventional vortex patterns in the two-gap MgB2 superconductor, in PHYSICAL REVIEW B, 85(9), 094511-094521.
Quantum oscillations of the superconductor LaRu2P2: Comparable mass enhancement lambda approximate to 1 in Ru and Fe phosphides
Moll PJW, Kanter J, McDonald RD, Balakirev F, Blaha P, Schwarz K, Bukowski Z, Zhigadlo ND, Katrych S, Mattenberger K, Karpinski J, Batlogg B (2011), Quantum oscillations of the superconductor LaRu2P2: Comparable mass enhancement lambda approximate to 1 in Ru and Fe phosphides, in PHYSICAL REVIEW B, 84(22), 224507-224517.
Time-resolved femtosecond optical characterization of multi-photon absorption in high-pressure-grown Al0.86Ga0.14N single crystals
Zhang J, Belousov A, Karpinski J, Batlogg B, Wicks G, Sobolewski R (2011), Time-resolved femtosecond optical characterization of multi-photon absorption in high-pressure-grown Al0.86Ga0.14N single crystals, in JOURNAL OF APPLIED PHYSICS, 110(11), 113112-113117.
Effect of carbon substitution on low magnetic field AC losses in MgB2 single crystals
Ciszek M, Rogacki K, Karpinski J (2011), Effect of carbon substitution on low magnetic field AC losses in MgB2 single crystals, in PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 471(21-22), 794-797.
Interplay between magnetism and superconductivity in EuFe2-xCoxAs2 studied by Fe-57 and Eu-151 Mossbauer spectroscopy
Blachowski A, Ruebenbauer K, Zukrowski J, Bukowski Z, Rogacki K, Moll PJW, Karpinski J (2011), Interplay between magnetism and superconductivity in EuFe2-xCoxAs2 studied by Fe-57 and Eu-151 Mossbauer spectroscopy, in PHYSICAL REVIEW B, 84(17), 174503-174513.
Interplay of composition, structure, magnetism, and superconductivity in SmFeAs1-xPxO1-y
Zhigadlo ND, Katrych S, Bendele M, Moll PJW, Tortello M, Weyeneth S, Pomjakushin VY, Kanter J, Puzniak R, Bukowski Z, Keller H, Gonnelli RS, Khasanov R, Karpinski J, Batlogg B (2011), Interplay of composition, structure, magnetism, and superconductivity in SmFeAs1-xPxO1-y, in PHYSICAL REVIEW B, 84(13), 134526-134536.
Anisotropic magnetic order of the Eu sublattice in single crystals of EuFe2-xCoxAs2 (x=0,0.2) studied by means of magnetization and magnetic torque
Guguchia Z, Bosma S, Weyeneth S, Shengelaya A, Puzniak R, Bukowski Z, Karpinski J, Keller H (2011), Anisotropic magnetic order of the Eu sublattice in single crystals of EuFe2-xCoxAs2 (x=0,0.2) studied by means of magnetization and magnetic torque, in PHYSICAL REVIEW B, 84(14), 144506-144516.
Muon-spin rotation measurements of the magnetic penetration depth in the iron-based superconductor Ba1-xRbxFe2As2
Guguchia Z, Shermadini Z, Amato A, Maisuradze A, Shengelaya A, Bukowski Z, Luetkens H, Khasanov R, Karpinski J, Keller H (2011), Muon-spin rotation measurements of the magnetic penetration depth in the iron-based superconductor Ba1-xRbxFe2As2, in PHYSICAL REVIEW B, 84(9), 094513-094523.
Tuning of competing magnetic and superconducting phase volumes in LaFeAsO0.945F0.055 by hydrostatic pressure
Khasanov R, Sanna S, Prando G, Shermadini Z, Bendele M, Amato A, Carretta P, De Renzi R, Karpinski J, Katrych S, Luetkens H, Zhigadlo ND (2011), Tuning of competing magnetic and superconducting phase volumes in LaFeAsO0.945F0.055 by hydrostatic pressure, in PHYSICAL REVIEW B, 84(10), 100501-100511.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
From Solid State to Biophysics 09.06.2012 Cavtat Kroatia
Kick-off meeting of Super-Iron 12.12.2011 Genova
XV Superconductivity School 09.10.2011 Kazimierz, Poland
EMRS meeting 19.09.2011 Warsaw, Poland
Swiss Physical Society Meeting 15.06.2011 Lausanne, Switzerland
MRS Spring Meeting 25.04.2011 San Francisco, USA


Awards

Title Year
Full Professor Titel (Poland) 2011

Associated projects

Number Title Start Funding scheme
141962 Mott Physics Beyond the Heisenberg Model in Iridates and Related Materials 01.01.2013 Sinergia
140760 Crystal growth, structural and physical investigations of novel superconductors and related compounds 01.07.2012 Project funding (Div. I-III)
124616 FeAs based superconductors: Single crystal growth, structural and physical properties investigations 01.04.2009 Project funding (Div. I-III)
124616 FeAs based superconductors: Single crystal growth, structural and physical properties investigations 01.04.2009 Project funding (Div. I-III)
117815 High pressure crystal growth, thermodynamics and physical properties of (A1, Ga)N and (In, Ga)N semiconductors 01.10.2007 Project funding (Div. I-III)

Abstract

Since the first report on superconductivity at 26 K in F-doped LaFeAsO at the end of February 2008, the superconducting transition temperature has been quickly raised to about 55 K and many new superconductors have been found. Superconductors with higher critical temperature might be expected. Superconductors and related compounds of high current interest derive their electronic properties from a rather complex interplay of electronic states that are associated with the various constituents that make up the unit cell. Both chemical and structural subtleties can play a decisive role, and require a thorough and systematic study. Our aims are synthesis and investigations of structural properties of single crystals and polycrystalline samples of strongly anisotropic compounds such as high temperature or novel superconductors, FeAs based and related compounds. The study of the influence of chemical substitutions on the superconducting properties is also the aim of the project. By substituting a small amount of foreign elements in the structure one can vary the electron count, create defects or modify the electronic structure leading to an increase of the upper critical field Hc2 or critical temperature and variation of other superconducting parameters. Our aims are to grow single crystals and to synthesize polycrystalline samples of pnictides superconductors for investigations of structural and anisotropic physical properties. We will also perform systematic search for new superconductors. In addition to our own investigations of the material, we also collaborate with many laboratories, both in Switzerland and around the world. As we are one of few labs growing such crystals, there is a worldwide interest for collaboration with our group. In the last years, the interest in column III-nitride materials has become of technical significance due to their optical and electrical properties. In the field of energy efficient lighting, and related applications, there is currently a great need of solid-state light emitters with wavelength in the blue-ultraviolet range. Many nitride-based devices include heterostructures involving binary or ternary alloys of GaN, AlN and InN. In particular, ternaries such as (Al,Ga)N are a class of key materials, and conductive n-type and p-type (Al,Ga)N alloys with high Al contents are especially important for applications. Using high nitrogen pressure and high temperature solution growth technique we were able to grow for the first time (Al,Ga)N single crystals and thick epitaxialy oriented layers on the AlN substrate. Thick layer, subsequently separated from the substrate, can be used for epitaxial growth of device heterostructures or as a seed for the growth of larger crystals. Growth of crystals and layers and investigations of their physical properties will be the subject of the proposed research project.
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