Experimental critical exponents of "pure" ferromagnets: The cost of excessive proximity to TC may be too high

Europhysics Letters

Volumn 73, Issue 3, 2006, Pages 396-400

  Kuz'Min, M D ^a   Tishin, A M ^b  

^a IFW DRESDEN   (Germany)

^b MOSCOW STATE UNIVERSITY   (Russian Federation)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 31944432150     PISSN: 02955075     EISSN: None     Source Type: Journal    
DOI: 10.1209/epl/i2005-10409-3     Document Type: Article

References (14)

1. PAČES J., Czech. J. Phys., 7 (1957) 729.
2. BELOV K. P., Magnetic Transitions (Consultants Bureau, New York) 1961, Chapt. III, sect. 8.
3. ROMANOV A. YU., SILIN V. P. and WAGNER D., Phys. Lett. A, 226 (1997) 310.
4. STANLEY H. E., Introduction to Phase Transitions and Critical Phenomena (Oxford University Press, London) 1971.
5. For simplicity the more complex logarithmic singularities are not considered herein.
6. eff(ε), conjectured crossovers in the limit ε → 0 to hypothetical modes to account for the unusual values of λ, etc. For details see refs. [7,8] and references therein.
7. SEEGER M., KAUL S. N., KRONMÜLLER H. and REISSER R., Phys. Rev. B, 51 (1995) 12585.
8. SRINATH S. and KAUL S. N., Phys. Rev. B, 60 (1999) 12166.
9. HARRIS A. B., J. Phys. C, 7 (1974) 1671.
10. In the particular case of microscopic inhomogeneity one would have x̄ ≫ Δx → 0, and thence Δ → 0, i.e. a single Curie point. Our consideration, however, is not restricted to such idealized systems.
11. BOZORTH R. M., Ferromagnetism (Van Nostrand, New York) 1951.
12. ABRAMOWITZ M. and STEGUN I. A., Handbook of Mathematical Functions (Dover, New York) 1972.
13. In this letter β= 1/3 is used merely as an example. There is, however, ample experimental evidence of this being approximately true at least for metallic ferromagnets, see KUZ'MIN M. D., Phys. Rev. Lett., 94 (2005) 107204.
14. The doubt does not concern the experimental data of refs. [7,8], only the data treatment and conclusions. Re-thinking the strategy and extrapolating in fig. 9 of ref. [7] towards larger |ε|, rather than to zero, one would get for β a value close to 1/3.