In:
Journal of Applied Physics, AIP Publishing, Vol. 95, No. 11 ( 2004-06-01), p. 7537-7539
Abstract:
The field-induced antiferromagnetic phase transitions in NiCl24SC(NH2)2 have been determined in fields up to 18 T and temperatures down to 0.016 K. This is an S=1 system with a singlet ground state separated from an excited doublet by D/kB. In zero field this spin-gap system remains nonmagnetic down to T=0, because the small antiferromagnetic exchange interaction (J) is “subcritical” (2zJ & lt;D). However, a magnetic field applied along the uniaxial direction lowers one of the excited energy levels, thus creating a condition for the establishment of long-range order. At T=0 this happens between B1=2.11±0.01 T and B2=12.11±0.03 T. The onset of this long-range order has been treated as Bose–Einstein condensation of magnons. The phase-boundaries B1(T) and B2(T) determined follow power-law dependence, Bi(T)−Bi(0)∝Tφ, with φ=2.6±0.2 for both.
Type of Medium:
Online Resource
ISSN:
0021-8979
,
1089-7550
Language:
English
Publisher:
AIP Publishing
Publication Date:
2004
detail.hit.zdb_id:
220641-9
detail.hit.zdb_id:
3112-4
detail.hit.zdb_id:
1476463-5
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