Publications of R. Helfrich

Gegenwart, P.; Langhammer, C.; Helfrich, R.; Oeschler, N.; Lang, M.; Kim, J. S.; Stewart, G. R.; Steglich, F.: Non-Fermi liquid normal state of the heavy-fermion superconductor UBe₁₃. Physica C 408-410, pp. 157 - 160 (2004)

Müller, J.; Lang, M.; Helfrich, R.; Steglich, F.; Sasaki, T.: High-resolution ac-calorimetry studies on κ-(ET)₂Cu(NCS)₂: a strong-coupling superconductor with finite energy gap. Synthetic Metals 133, pp. 235 - 237 (2003)

Müller, J.; Lang, M.; Helfrich, R.; Steglich, F.; Sasaki, T.: High-resolution ac-calorimetry studies of the quasi-two- dimensional organic superconductor kappa-(BEDT- TTF)₂Cu(NCS)₂. Physical Review B 65 (14), 140509, p. 140509 - 140509 (2002)

Köppen, M.; Lang, M.; Helfrich, R.; Steglich, F.; Thalmeier, P.; Schmidt, B.; Wand, B.; Pankert, D.; Benner, H.; Aoki, H. et al.; Ochiai, A.: Solitary Magnetic Excitations in the Low-Carrier Density, One-Dimensional S = 1/2 Antiferromagnet Yb₄As₃. Physical Review Letters 82 (22), pp. 4548 - 4551 (1999)

Lang, M.; Helfrich, R.; Kromer, F.; Langhammer, C.; Steglich, F.; Stewart, G. R.; Kim, J. S.: New results on the low-T phase diagram of U_1-xTh_xBe₁₃: A thermodynamic study. Physica B 259-261, pp. 608 - 613 (1999)

Gegenwart, P.; Langhammer, C.; Geibel, C.; Helfrich, R.; Lang, M.; Sparn, G.; Steglich, F.; Horn, R.; Donnevert, L.; Link, A. et al.; Assmus, W.: Breakup of Heavy Fermions on the Brink of "Phase A" in CeCu₂Si₂. Physical Review Letters 81 (7), pp. 1501 - 1504 (1998)

Helfrich, R.; Köppen, M.; Lang, M.; Steglich, F.; Ochiai, A.: New observations concerning the low-temperature properties of the carrier-poor heavy-fermion system Yb₄As₃. Journal of Magnetism and Magnetic Materials 177-181, pp. 309 - 310 (1998)

Kromer, F.; Helfrich, R.; Lang, M.; Steglich, F.; Langhammer, C.; Bach, A.; Michels, T.; Kim, J. S.; Stewart, G. R.: UBe₁₃: Another Phase Transition below T_C? Chinese Journal of Physics 36 (2), pp. 157 - 170 (1998)

Kromer, F.; Helfrich, R.; Lang, M.; Steglich, F.; Langhammer, C.; Bach, A.; Michels, T.; Kim, J. S.; Stewart, G. R.: Revision of the Phase Diagram of Superconducting U_1-xTh_xBe₁₃. Physical Review Letters 81 (20), pp. 4476 - 4479 (1998)

Langhammer, C.; Helfrich, R.; Bach, A.; Kromer, F.; Lang, M.; Michels, T.; Deppe, M.; Steglich, F.; Stewart, G. R.: Evidence for the existence of two variants of UBe₁₃. Journal of Magnetism and Magnetic Materials 177-181, pp. 443 - 444 (1998)

Steglich, F.; Geibel, C.; Helfrich, R.; Kromer, F.; Lang, M.; Sparn, G.; Gegenwart, P.; Donnevert, L.; Langhammer, C.; Link, A. et al.; Kim, J. S.; Stewart, G. R.: CeCu₂Si₂ And UBe₁₃: New Questions - Old Answers? Journal of Physics and Chemistry of Solids 59 (10-12), pp. 2190 - 2195 (1998)

Aoki, H.; Ochiai, A.; Suzuki, T.; Helfrich, R.; Steglich, F.: Systematic study in mixed valence system Yb₄(As_1-xSb_x)₃. Physica B 230-232, pp. 698 - 701 (1997)

Gegenwart, P.; Lohmann, M.; Lang, M.; Helfrich, R.; Langhammer, C.; Köppen, M.; Geibel, C.; Steglich, F.; Assmus, W.: Non-Fermi-liquid behavior in CeCu₂Si₂ at the disappearance of the presumably magnetically ordered "A-phase". Physica B 203-232, pp. 572 - 575 (1997)

Ochiai, A.; Aoki, H.; Suzuki, T.; Helfrich, R.; Steglich, F.: Strongly correlated electron system without free carrier Yb₄(As_1-xP_x)₃. Physica B 230-232, pp. 708 - 710 (1997)

Steglich, F.; Gegenwart, P.; Helfrich, R.; Langhammer, C.; Hellmann, P.; Donnevert, L.; Geibel, C.; Lang, M.; Sparn, G.; Assmus, W. et al.; Stewart, G. R.; Ochiai, A.: Are heavy-fermion metals Fermi liquids? Zeitschrift für Physik B 103, pp. 235 - 247 (1997)

Steglich, F.; Hellmann, P.; Thomas, S.; Gegenwart, P.; Link, A.; Helfrich, R.; Sparn, G.; Lang, M.; Geibel, C.; Assmus, W.,.: "Non-Fermi-liquid" phenomena in heavy-fermion CeCu₂Si₂ and CeNi₂Ge₂. Physica B 237-238, pp. 192 - 196 (1997)

Lang, M.; Gegenwart, P.; Helfrich, R.; Köppen, M.; Kromer, F.; Langhammer, C.; Geibel, C.; Steglich, F.; Kim, J. S.; Stewart, G. R.: Non-Fermi-Liquid properties and exotic Superconductivity in CeCu₂Si₂ and (UTh)Be₁₃. In: Electronic Correlations and Materials Properties (Ed. Gonis, A.). Kluwer/Plenum, New York (1999)