Magnetic-ordered and superconducting units inside surface layers of PbTe:Eu crystals grown from melt by using the Bridgman method

• Veröffentlicht in: Semiconductor Physics Quantum Electronics & Optoelectronics
• Datum: 2013
• Hauptverfasser: Zayachuk, D.M., Ilyina, O.S., Kaczorowski, D., Mikityuk, V.I., Shlemkevych, V.V.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2013
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/117810
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Magnetic-ordered and superconducting units
 inside surface layers of PbTe:Eu crystals grown from melt
 by using the Bridgman method / D.M. Zayachuk, O.S. Ilyina, D. Kaczorowski, V.I. Mikityuk, and V.V. Shlemkevych // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2013. — Т. 16, № 4. — С. 336-343. — Бібліогр.: 18 назв. — англ.

Presented in this work are the results of the first systematic study of magnetic
 properties inherent to surface layers of PbTe:Eu crystals grown from melt with a low
 initial concentration of Eu impurity using the Bridgman
 method. The magnetic field dependences of magnetization at the temperature 1.72 K and
 temperature dependences of magnetic susceptibility within the temperature range 1.7 to
 10 K of the surface powder samples has been investigated. Inside the surface layers,
 formation of both small magnetic complexes based on Eu impurity and lead-based
 inclusions superconducting at low temperatures, which originate in a correlated way
 during the growth process of doped ingots, has been established. The observed
 correlations are manifested in a consistent distribution of both europium-based and leadbased
 units along the lateral surface, where the probability of their formation increases
 towards the end of the doped ingot. Based on the analysis of the obtained magnetic data,
 it has been suggested that the lead-based inclusions, being formed within the surface
 layer of PbTe:Eu crystals during the process of their growth and passing into a
 superconducting state on cooling, are the type II superconductors with a very high top
 critical field Hc₂ at low temperatures. At T = 1.7 K, Hc₂ of the inclusions is estimated to
 exceed 50.0 kOe. The important role of the background oxygen impurity in format 
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