Magnetic state, transport properties and structure of granular nanophased systems / Yermakov AY,Uimin MA,Mushnikov NV,Zajkov NK,Serikov VV,Korobejnikov AY,Kleinerman NM,Shtolz AK // . - 1998. - V. 50, l. . - P. 425-440.

ISSN/EISSN:

нет данных / нет данных

Type:

Proceedings Paper

Abstract:

In this paper we report the investigation on the formation, if any, of supersaturated solid solution by mechanical alloying of Cu-20\%Co and by hydrogenation of Pr(Co,Cu)(5) intermetallics. A comparative analysis of structure and magnetic properties of above mentioned systems are performed. The structural state of Cu80Co20 system after mechanical alloying and a subsequent thermal treatment has been studied by NMR-spectroscopy and X-ray diffraction. Analysis of the data obtained as well as magnetic and magnetoresistive properties make it possible to assume the formation of ultradispersed cobalt clusters in a copper matrix. A partial dissolving of cobalt in copper is likely to take place in defect regions. Such a structure is responsible for superparamagnetism of Cug(80)Co(20) system at T > 150 K and for a considerable giant magnetoresistance (GMR) effect (12\% at T = 77 K). A shift of X-ray peaks of a copper matrix can partially be due to a coherence of Cu and Co phases. Quasi-binary Pr(Co1-xCux)(5) intermetallics with 0 less than or equal to x less than or equal to 1 were hydrogenated at elevated temperatures to precipitate Co and Cu and to study their mutual solubility. Low temperature hydrogenation was found to form a CaCu5-type hydride containing about 1.6 hydrogen atoms per formula unit. Above 500 degrees C the sample decomposed into PrH2.6, Cu and HCP-Co. In the temperature range 330 - 450 degrees C the CaCu5-type hydride coexisted with the decomposed phases. Structural and magnetic measurements indicated that no solid solution was formed in Co-Cu decomposed phases. The magnetoresistance on both parent and hydrogenated samples did not exceed 0.5 \%.

Author keywords:

mechanical alloying; hydrogenation; crystal structure; decomposition; Cu-Co; Pr(Co1-xCUx)(5); magnetic properties; magnetoresistance

DOI:

нет данных

Web of Science ID:

ISI:000075454000021

Соавторы в МНС:

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Другие поля

Поле	Значение
Editor	Chow, GM and Noskova, NI
Booktitle	NANOSTRUCTURED MATERIALS: SCIENCE \& TECHNOLOGY
Series	NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY
Note	NATO Advanced Study Institute on Nanostructured Materials - Science and Technology, ST PETERSBURG, RUSSIA, AUG 10-20, 1997
Organization	NATO, Sci Comm; NATO, High Technol Area Program; USN, Off Naval Res; US Natl Sci Fdn; Russian Acad Sci; Russian Fdn Basic Res; Amer Soc Engn Educ; Adv Mat \& Technol Fdn, Russia
Publisher	SPRINGER
Address	PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS
Language	English
ISBN	0-7923-5071-5
Research-Areas	Engineering; Materials Science; Metallurgy \& Metallurgical Engineering
Web-of-Science-Categories	Engineering, Multidisciplinary; Materials Science, Ceramics; Materials Science, Multidisciplinary; Metallurgy \& Metallurgical Engineering; Materials Science, Characterization \& Testing
ResearcherID-Numbers	Mushnikov, Nikolay/K-9076-2013 Uimin, Mikhail/K-1319-2013 Yermakov, Anatoly/J-5185-2013 Kleinerman, Nadezhda/J-4709-2013 Serikov, Vadim/J-8509-2013
ORCID-Numbers	Mushnikov, Nikolay/0000-0002-6354-2558 Uimin, Mikhail/0000-0003-3906-8101 Yermakov, Anatoly/0000-0001-6466-7064 Kleinerman, Nadezhda/0000-0002-4482-0700 Serikov, Vadim/0000-0003-1999-6285
Doc-Delivery-Number	BL42D