Specific heat study of the magnetocaloric effect in the Haldane-gap S=1 spin-chain material [Ni(C2H8N2)(2)NO2](BF4)
Result description
Magnetocaloric effect in the Haldane-gap S = 1 spin-chain [Ni(C2H8N2)(2)NO2](BF4) was investigated at low temperatures (k(B)T << J) and magnetic fields up to nominally 0.1B(sat), where J and B-sat denote an exchange interaction and saturation magnetic field, respectively. Magnetic entropy was found to scale as exp(Delta/k(B)T) in zero magnetic field and T-0.67 for B = B-c, in which the Haldane gap should be closed, in reasonable agreement with the theoretical predictions. The existence of the inverse magnetocaloric effect for B < B-c was confirmed. The occurrence of normal magnetocaloric response at lowest temperatures and magnetic fields was attributed to S = 1/2 degrees of freedom arising from the ends of chain segments.
Keywords
NiC2H8N22NO2BF4materialspin-chainS=1Haldane-gapeffectmagnetocaloricstudyheatSpecific
The result's identifiers
Result code in IS VaVaI
Result on the web
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Specific heat study of the magnetocaloric effect in the Haldane-gap S=1 spin-chain material [Ni(C2H8N2)(2)NO2](BF4)
Original language description
Magnetocaloric effect in the Haldane-gap S = 1 spin-chain [Ni(C2H8N2)(2)NO2](BF4) was investigated at low temperatures (k(B)T << J) and magnetic fields up to nominally 0.1B(sat), where J and B-sat denote an exchange interaction and saturation magnetic field, respectively. Magnetic entropy was found to scale as exp(Delta/k(B)T) in zero magnetic field and T-0.67 for B = B-c, in which the Haldane gap should be closed, in reasonable agreement with the theoretical predictions. The existence of the inverse magnetocaloric effect for B < B-c was confirmed. The occurrence of normal magnetocaloric response at lowest temperatures and magnetic fields was attributed to S = 1/2 degrees of freedom arising from the ends of chain segments.
Czech name
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Czech description
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Classification
Type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10302 - Condensed matter physics (including formerly solid state physics, supercond.)
Result continuities
Project
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Physical Review B
ISSN
2469-9950
e-ISSN
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Volume of the periodical
96
Issue of the periodical within the volume
9
Country of publishing house
US - UNITED STATES
Number of pages
7
Pages from-to
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UT code for WoS article
000411291700005
EID of the result in the Scopus database
2-s2.0-85029946746
Basic information
Result type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
OECD FORD
Condensed matter physics (including formerly solid state physics, supercond.)
Year of implementation
2017