Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity

We present the results of our extensive Mössbauer effect studies carried out on a wide variety of mixed valence manganites as well as other types of magnetoresistive materials, including pyrochlore Tl₂Mn₂O₇ and the chalcospinels Fe₀.₅Cu₀.₅Cr₂S₄ and FeCr₂S₄ with absolutely different natures of the ma...

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Опубліковано в: :Физика низких температур
Дата:2002
Автори: Chechersky, V., Nath, A.
Формат: Стаття
Мова:English
Опубліковано: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2002
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Онлайн доступ:https://nasplib.isofts.kiev.ua/handle/123456789/130233
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Цитувати:Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity / V. Chechersky, A. Nath // Физика низких температур. — 2002. — Т. 28, № 7. — С. 781-789. — Бібліогр.: 56 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-130233
record_format dspace
spelling Chechersky, V.
Nath, A.
2018-02-09T10:50:19Z
2018-02-09T10:50:19Z
2002
Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity / V. Chechersky, A. Nath // Физика низких температур. — 2002. — Т. 28, № 7. — С. 781-789. — Бібліогр.: 56 назв. — англ.
0132-6414
PACS: 76.80.+y
https://nasplib.isofts.kiev.ua/handle/123456789/130233
We present the results of our extensive Mössbauer effect studies carried out on a wide variety of mixed valence manganites as well as other types of magnetoresistive materials, including pyrochlore Tl₂Mn₂O₇ and the chalcospinels Fe₀.₅Cu₀.₅Cr₂S₄ and FeCr₂S₄ with absolutely different natures of the magnetism, in a search for similarities linked to their magnetoresistive behavior. The double exchange electron transfer and coupling between the electrons and Jahn–Teller lattice distortions invoked by most theories to explain the colossal magnetoresistivity and associated metal–insulator transition in manganites are not applicable to pyrochlore nor to chalcospinels. Nevertheless, we find intriguing similarities in the anomalous magnetic and dynamic behavior among these widely different systems at, above, and below the Curie temperature Tc, which shed light on the origin of bulk magnetoresistivity in general. All these compounds share the following features. The long-range ferromagnetic order breaks down even below the Curie temperature, with the formation of nano-size spin clusters. Softening of the lattice was observed near Tc. The short-range interactions in these spin clusters survive well above Tc. When an external magnetic field is applied, the spin clusters coalesce to form large clusters, with considerable lowering of the resistivity. There is a strong evidence that the existence of nano-size spin clusters with superparamagnetic-like behavior near Tc is a prerequisite for the occurrence of bulk magnetoresistivity.
AN thanks the donors of the PRF administered by ACS for partial support of this research.
en
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
Физика низких температур
Дефекты в кристаллах
Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity
spellingShingle Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity
Chechersky, V.
Nath, A.
Дефекты в кристаллах
title_short Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity
title_full Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity
title_fullStr Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity
title_full_unstemmed Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity
title_sort anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity
author Chechersky, V.
Nath, A.
author_facet Chechersky, V.
Nath, A.
topic Дефекты в кристаллах
topic_facet Дефекты в кристаллах
publishDate 2002
language English
container_title Физика низких температур
publisher Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
format Article
description We present the results of our extensive Mössbauer effect studies carried out on a wide variety of mixed valence manganites as well as other types of magnetoresistive materials, including pyrochlore Tl₂Mn₂O₇ and the chalcospinels Fe₀.₅Cu₀.₅Cr₂S₄ and FeCr₂S₄ with absolutely different natures of the magnetism, in a search for similarities linked to their magnetoresistive behavior. The double exchange electron transfer and coupling between the electrons and Jahn–Teller lattice distortions invoked by most theories to explain the colossal magnetoresistivity and associated metal–insulator transition in manganites are not applicable to pyrochlore nor to chalcospinels. Nevertheless, we find intriguing similarities in the anomalous magnetic and dynamic behavior among these widely different systems at, above, and below the Curie temperature Tc, which shed light on the origin of bulk magnetoresistivity in general. All these compounds share the following features. The long-range ferromagnetic order breaks down even below the Curie temperature, with the formation of nano-size spin clusters. Softening of the lattice was observed near Tc. The short-range interactions in these spin clusters survive well above Tc. When an external magnetic field is applied, the spin clusters coalesce to form large clusters, with considerable lowering of the resistivity. There is a strong evidence that the existence of nano-size spin clusters with superparamagnetic-like behavior near Tc is a prerequisite for the occurrence of bulk magnetoresistivity.
issn 0132-6414
url https://nasplib.isofts.kiev.ua/handle/123456789/130233
citation_txt Anomalous magnetic and dynamic behavior in magnetoresistive compounds: origin of bulk colossal magnetoresistivity / V. Chechersky, A. Nath // Физика низких температур. — 2002. — Т. 28, № 7. — С. 781-789. — Бібліогр.: 56 назв. — англ.
work_keys_str_mv AT checherskyv anomalousmagneticanddynamicbehaviorinmagnetoresistivecompoundsoriginofbulkcolossalmagnetoresistivity
AT natha anomalousmagneticanddynamicbehaviorinmagnetoresistivecompoundsoriginofbulkcolossalmagnetoresistivity
first_indexed 2025-12-07T17:29:32Z
last_indexed 2025-12-07T17:29:32Z
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