Dimensionality crossovers in the magnetization of the weakly ferromagnetic two-dimensional manganese alkylphosphonate hydrates MnC<sub>n</sub>H<sub>2n+1</sub>PO<sub>3</sub>.H<sub>2</sub>O, n=2-4
S G Carling; P Day; D Visser; S G Carling; R. Inst., London, UK; P Day; R. Inst., London, UK; D Visser; R. Inst., London, UK
Журнал:
Journal of Physics: Condensed Matter
Дата:
1995-02-27
Аннотация:
Critical exponents of magnetization beta below T<sub>N</sub> in the weakly ferromagnetic layer compounds MnC<sub>n</sub>H<sub>2n+1</sub>PO<sub>3</sub>.H<sub>2</sub>O have been measured by SQUID magnetometry for n=2-4. In all three compounds crossovers are observed in beta as follows ( beta <sub>1</sub>, beta <sub>2</sub>): 0.21(2), 0.73(2) (n=2); 0.18(1), 0.42(6) (n=3), 0.18(1), approximately 0.6 (n=4). The crossover occurs at values of the reduced temperature epsilon =(T<sub>N</sub>-T)/T<sub>N</sub> that become smaller as the separation between the magnetic layers increases.
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