Microscopic theory for the fluctuation-driven phase transition in weak itinerant magnets

Conference · Mon Oct 01 04:00:00 EDT 1973

OSTI ID:4380734

Murata, K K

From 19th conference on magnetism and magnetic materials; Boston, Massachusetts, USA (13 Nov 1973). The microscopic basis for a recent phenomenological theory -for the thermodynamics near T/sub c/ of weak itinerant magnets is presented. Calculation of dynamic renormalization effects within paramagnon theory justifies the previous assumption of weakly temperature dependent Ginsburg- Landau alpha and BETA coefficients. The cutoff on the fluctuation phase space is found to go as q/sub m/= ~ (T/sub c/)/sup 1/3/ rather than the usual inverse coherence length. In spite of the phase space reduction, as T/sub c/ yields -- 0, the phenomenological description becomes exact in a temperature region of order T/sub c/. However, it is found that the alpha and BETA coefficients must be determined phenomenologically since no small parameter enters the calculation of their overall magnitude. (auth)

• Research Organization: Brookhaven National Lab., Upton, N.Y. (USA)
• NSA Number: NSA-29-006381
• OSTI ID: 4380734
• Report Number(s): BNL--18281; CONF-731104--3
• Country of Publication: United States
• Language: English

Related Subjects

*SUPERCONDUCTING MAGNETS-- PHASE TRANSFORMATIONS
GINZBURG-LANDAU THEORY
N66300* --Physics (Low Temperature)--Equipment & Devices
RENORMALIZATION
TEMPERATURE DEPENDENCE
THERMODYNAMICS
TRANSITION TEMPERATURE
VARIATIONS