Pressure-tuned spin and charge ordering in an itinerant antiferromagnet
Elemental chromium orders antiferromagnetically near room temperature, but the ordering temperature can be driven to zero by applying large pressures. We combine diamond anvil cell and synchrotron x-ray diffraction techniques to measure directly the spin and charge order in the pure metal at the approach to its quantum critical point. Both spin and charge order are suppressed exponentially with pressure, well beyond the region where disorder cuts off such a simple evolution, and they maintain a harmonic scaling relationship over decades in scattering intensity. By comparing the development of the order parameter with that of the magnetic wave vector, it is possible to ascribe the destruction of antiferromagnetism to the growth in electron kinetic energy relative to the underlying magnetic exchange interaction.
Additional Information© 2007 The American Physical Society. (Received 10 June 2007; published 24 September 2007) The work at the University of Chicago was under NSF Grant No. DMR-0534296. G.A. acknowledges the Royal Society for financial support. R. J. thanks the NSF Graduate Research program for financial support. Use of APS is supported by the U. S. DOE-BES, under Contract No. NE-AC02-06CH11357. Use of HPCAT is supported by DOE-BES, CDAC, NSF, and the W. M. Keck Foundation.
Published - PhysRevLett.99.137201.pdf
Submitted - 0708.1778v1.pdf