Hauf, C.; Kniep, R.; Pfaff, G.: Preparation of various titanium suboxide powders by reduction of TiO₂ with silicon. Journal of Materials Science 34, S. 1287 - 1292 (1999)

Hiess, A.; Coad, S.; Buschinger, B.; Trovarelli, O.; Boucherle, J. X.; Givord, F.; Hansen, T.; Lelievre-Berna, E.; Suard, E.; Geibel, C. et al.; Steglich, F.: Magnetism in R₂T₃X₉ (R = Ce, Yb, U; T = Rh, Ir; X = Al, Ga) intermetallic compounds. Physica B 259-261, S. 343 - 344 (1999)

Ishida, K.; Kawasaki, Y.; Tabuchi, K.; Kashima, K.; Kitaoka, Y.; Asayama, K.; Geibel, C.; Steglich, F.: Crossover behaviour from magnetism to superconductivity in Ce_xCu₂Si₂. Physica B 259-261, S. 678 - 680 (1999)

Ishida, K.; Kawasaki, Y.; Tabuchi, K.; Kashima, K.; Kitaoka, Y.; Asayama, K.; Geibel, C.; Steglich, F.: Evolution from Magnetism to Unconventional Superconductivity in a Series of Ce_xCu₂Si₂ Compounds Probed by Cu NQR. Physical Review Letters 82, S. 5353 - 5356 (1999)

Ishida, K.; Kitaoka, Y.; Kawasaki, Y.; Tabuchi, K.; Kashima, K.; Asayama, K.; Geibel, C.; Steglich, F.: Evolution from Magnetically Ordered to Unconventional Superconducting Phase in a Series of Ce_xCu₂Si₂ Compounds: Cu-NQR Study. JJAP Series 11, S. 35 - 37 (1999)

Klatyk, J.; Kniep, R.: Crystal structure of alkaline earth dilithium bis(nitridolithiate/ferrate(I)), Ca{Li₂[(Li_1-xFe_x)N]₂}, x = 0,30 and Sr{Li₂[(Li_1-xFe_x)N]₂}, x = 0,46. Zeitschrift für Kristallographie - New Crystal Structures 214, S. 449 - 450 (1999)

Klatyk, J.; Kniep, R.: Crystal structure of dicalcium (dinitriodolithiate/ferrate(I)) Ca₂{Li[(Li_1-xFe_x)N₂]}, x = 0,82. Zeitschrift für Kristallographie - New Crystal Structures 214, S. 451 - 452 (1999)

Klatyk, J.; Kniep, R.: Crystal structure of dilithium (nitridolithiate/ferrate(I)), Li₂[(Li_1-xFe_x)N], x = 0,63. (1999)

Klatyk, J.; Kniep, R.: Crystal structure of dilithium (nitridolithiate/manganate(I)), Li₂[(Li_1-xMn_x)N], x = 0,73. Zeitschrift für Kristallographie - New Crystal Structures 214, S. 445 - 446 (1999)

Kniep, R.; Boy, I.; Engelhardt, H.: RbFe[BP₂O₈(OH)]: Ein neues Borophosphat mit offen-verzweigten Vierer-Einfach-Tetraederketten. Zeitschrift für Anorganische und Allgemeine Chemie 625, S. 1512 - 1516 (1999)

Kniep, R.; Schäfer, G.; Engelhardt, H.; Boy, I.: K[ZnBP₂O₈] and A[ZnBP₂O₈] (A = NH₄⁺, Rb⁺, Cs⁺): Zincoborophosphates as a New Class of Compounds with Tetrahedral Framework Structures. Angewandte Chemie, International Edition 38, S. 3641 - 3644 (1999)

Kniep, R.; Schäfer, G.; Engelhardt, H.; Boy, I.: K[ZnBP₂O₈] and A[ZnBP₂O₈] (A = NH₄⁺, Rb⁺, Cs⁺): Zinkoborophosphate als neue Klasse von Verbindungen mit Tetraeder-Gerüststrukturen. Angewandte Chemie 111, S. 3857 - 3961 (1999)

Köbler, U.; Hupfeld, D.; Schnelle, W.; Mattenberger, K.; Brückel, T.: Fourth-order exchange interactions in Gd_xEu_1-xS. Journal of Magnetism and Magnetic Materials 205, S. 90 - 104 (1999)

Koch, D.; Kniep, R.: Crystal structure of sodium aluminium (monohydrogenmonophosphate-dihydrogenmonoborate-monophosphate, NaAl[BP₂O₇(OH)₃]. Zeitschrift für Kristallographie - New Crystal Structures 214, S. 441 - 442 (1999)

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), S. 4548 - 4551 (1999)

Kremer, R. K.; Ahn, K.; Henn, R. W.; Mattausch, H.; Schnelle, W.; Stolovits, A.; Simon, A.: The rare-earth metal carbide halide superconductors RE₂C₂X₂ (RE = Y, La; X = Cl, Br, I). Physica C 317-318, S. 456 - 459 (1999)

Krishnamuthy, V. V.; Watanabe, I.; Nagamine, K.; Geibel, C.; Sparn, G.; Steglich, F.: μ⁺SR Study of heavy fermion magnetism in Ce(Cu_1-xNi_x)₂Ge₂. Hyperfine Interactions 120/121, S. 607 - 610 (1999)

Kromer, F.; Lang, M.; Steglich, F.; Kim, J. S.; Stewart, G. R.: A thermal-expansion study on the B-T phase diagrams of U_1-xTh_xBe₁₃ for 0 ≤ x ≤ 0.3. Physica B 259-261, S. 623 - 624 (1999)

Kvitnitskaya, O. E.; Naidyuk, Y. G.; Nowack, A.; Gloos, K.; Geibel, C.; Jansen, A. G. M.; Wyder, P.: Point-contact study of the heavy-fermion systems UPd₂Al₃ and UNi₂Al₃. Physica B 259-261, S. 638 - 639 (1999)

Landrum, G. A.; Dronskowski, R.; Niewa, R.; DiSalvo, F. J.: Electronic Structure and Bonding in Cerium (Nitride) Compounds: Trivalent versus Tetravalent Cerium. Chemistry - A European Journal 5, S. 515 - 522 (1999)