Crossover from random-exchange to random-field critical behavior in Ising models

Abstract

We compute the crossover exponent $\varphi$ describing the crossover from the random-exchange to the random-field critical behavior in Ising systems. For this purpose, we consider the field-theoretical approach based on the replica method, and perform a six-loop calculation in the framework of a fixed-dimension expansion. The crossover from random-exchange to random-field critical behavior has been observed in dilute anisotropic antiferromagnets, such as Fe${}_x$Zn${}_{1-x}$F${}_2$ and Mn${}_x$Zn${}_{1-x}$F${}_2$, when applying an external magnetic field. Our result $\varphi =1.42(2)$ for the crossover exponent is in good agreement with the available experimental estimates.

5 pages

References in corpus (4)

• Critical Phenomena and Renormalization-Group Theory
• Critical exponents of the three dimensional diluted Ising model
• Randomly dilute spin models: a six-loop field-theoretic study
• Summability of the perturbative expansion for a zero-dimensional disordered spin model

Cited by in corpus (7)

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• Ordered magnetism in the intrinsically decorated $j{}_{\mathrm{eff}}$ = $\frac{1}{2}$ $\alpha$-CoV${}_3$O${}_8$
• Spin models with random anisotropy and reflection symmetry
• Quasi-stationary criticality of the Order-Parameter of the d=3 Random-Field Ising Antiferromagnet Fe(0.85)Zn(0.15)F2: A Synchrotron X-ray Scattering Study
• Critical equation of state of randomly dilute Ising systems
• Static and dynamic structure factors in three-dimensional randomly diluted Ising models