Abstract
Following the recently published results (down to 0.3 K) on magnetic-field induced non-Fermi-liquid behavior in polycrystalline we present here specific heat C measurements down to on a single crystal. In the single crystal we find that in a critical magnetic field only along the magnetic easy (c) axis, where the long-range antiferromagnetic order in is just suppressed to a quantum critical point is reached with non-Fermi-liquid properties down to our lowest temperature of measurement. The lowest temperature data, for are proportional to a temperature dependence proposed in the Gaussian ( weakly interacting spin fluctuations) self-consistent renormalized spin-fluctuation theory. In contrast, the data at higher temperatures—including scaling with of both C and magnetization as a function of B—require a non-Gaussian strongly interacting spin-fluctuation model. In order to test this apparent crossover in behavior we have examined the scaling of for and find that the high-temperature scaling with (“hyperscaling”) does not function at the lowest temperatures.
- Received 14 July 1998
DOI:https://doi.org/10.1103/PhysRevB.58.R15959
©1998 American Physical Society