R. Helfrich

Max Planck Society — Germany

Physics and Astronomy · Physical Sciences

19h-index1.9kcitations30works0.02yr avg
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Research Topics

Rare-earth and actinide compounds(28), Iron-based superconductors research(25), Physics of Superconductivity and Magnetism(13), Magnetic Properties of Alloys(9), Inorganic Chemistry and Materials(5)

Publications30 total

Non-Fermi liquid normal state of the heavy-fermion superconductor UBe13
Physica C Superconductivity·2004· 25 citedOpen Access
High-resolution ac-calorimetry studies on κ-(ET)2Cu(NCS)2: a strong-coupling superconductor with finite energy gap
Synthetic Metals·2003
High-resolution ac-calorimetry studies of the quasi-two-dimensional organic superconductor<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>κ</mml:mi><mml:mo>−</mml:mo><mml:mo>(</mml:mo><mml:mi mathvariant="normal">BEDT</mml:mi><mml:mo>−</mml:mo><mml:mi mathvariant="normal">TTF</mml:mi><mml:mrow><mml:msub><mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mi mathvariant="normal">Cu</mml:mi><mml:mo>(</mml:mo><mml:mi mathvariant="normal">NCS</mml:mi><mml:mrow><mml:msub><mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>
Physical review. B, Condensed matter·2002· 81 citedOpen Access
Solitary Magnetic Excitations in the Low-Carrier Density, One-Dimensional<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">S</mml:mi><mml:mspace/><mml:mo>=</mml:mo><mml:mspace/><mml:mfrac><mml:mrow><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:mfrac></mml:math>Antiferromagnet<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>Yb</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>As</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>
Physical Review Letters·1999· 49 cited
New results on the low-T phase diagram of U1−xThxBe13: A thermodynamic study
Physica B Condensed Matter·1999· 12 cited
Non-Fermi-Liquid Properties and Exotic Superconductivity in CeCu2Si2 and (UTh)Be13
1999
Revision of the Phase Diagram of Superconducting<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">U</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi mathvariant="italic">x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Th</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Be</mml:mi></mml:mrow><mml:mrow><mml:mn>13</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>
Physical Review Letters·1998· 69 cited
CeCu2Si2 AND UBe13: NEW QUESTIONS—OLD ANSWERS?
Journal of Physics and Chemistry of Solids·1998· 7 cited
Breakup of Heavy Fermions on the Brink of “Phase<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">A</mml:mi></mml:math>” in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>CeCu</mml:mi><mml:mrow><mml:msub><mml:mrow><mml:mi/></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mi>Si</mml:mi><mml:mrow><mml:msub><mml:mrow><mml:mi/></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>
Physical Review Letters·1998· 160 citedOpen Access
New observations concerning the low-temperature properties of the carrier-poor heavy-fermion system Yb4As3
Journal of Magnetism and Magnetic Materials·1998· 34 cited
Evidence for the existence of two variants of UBe13
Journal of Magnetism and Magnetic Materials·1998· 13 cited
UBe13: another phase transition below Tc?
TUbilio (Technical University of Darmstadt)·1998· 1 cited
“Non-Fermi-liquid” phenomena in heavy-fermion CeCu2Si2 and CeNi2Ge2
Physica B Condensed Matter·1997· 21 citedOpen Access
Systematic study in mixed valence system Yb4(As1−xSbx)3
Physica B Condensed Matter·1997· 31 cited
Non-Fermi-liquid behavior in CeCu2Si2 at the disappearance of the presumably magnetically ordered “A-phase”
Physica B Condensed Matter·1997· 12 citedOpen Access
Strongly correlated electron system without free carrier Yb4(As1-xPx)3
Physica B Condensed Matter·1997· 30 cited
Coexistence of superconductivity and magnetism in CeCu 2 (Si 0.9 Ge 0.1 ) 2
Verhandlungen der Deutschen Physikalischen Gesellschaft·1997
Quantum critical phenomena in undoped heavy-fermion metals
Journal of Physics Condensed Matter·1996· 121 citedOpen Access
Superconductivity and antiferromagnetism in heavy-fermion metals: Coexistence and competition
Max Planck Digital Library·1996· 1 cited
New observations concerning magnetism and superconductivity in heavy-fermion metals
Physica B Condensed Matter·1996· 104 citedOpen Access
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Frequent Co-authors

F. Steglich(30), C. Geibel(16), Michael Lang(13), P. Gegenwart(12), Christoph Langhammer(12), G. R. Stewart(8), A. Grauel(7), W. Aßmus(7), Maik Lang(7), C. Schank(6), U. Ahlheim(6), G. Sparn(6), A. Link(6), F. Kromer(6), P. Hellmann(5), R. Modler(5), C.D. Bredl(4), L. Donnevert(4), A. Ochiai(4), M. Köppen(4)