Magnetic properties of URu{sub 2}Si{sub 2} under uniaxial stress by neutron scattering

Journal Article · Tue Nov 01 00:00:00 EDT 2011 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.84.184430· OSTI ID:21596918

Bourdarot, Frederic; Martin, Nicolas; Raymond, Stephane; Regnault, Louis-Pierre ^[1]; Aoki, Dai; Taufour, Valentin; Flouquet, Jacques ^[2]

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1. SPSMS, UMR-E 9001, CEA-INAC/ UJF-Grenoble 1, MDN, 17 rue des Martyrs, F-38054 Grenoble (France)
2. SPSMS, UMR-E 9001, CEA-INAC/ UJF-Grenoble 1, IMAPEC, 17 rue des Martyrs, F-38054 Grenoble (France)

The aim of this study is to compare the magnetic behavior of URu{sub 2}Si{sub 2} under uniaxial stress along the a axis with the behavior under hydrostatic pressure. Both are very similar, but uniaxial stress presents a critical stress {sigma}{sub x}{sup a}[0.33(5) GPa] that is smaller than the hydrostatic critical pressure p{sub x} (0.5 GPa) where the ground state switches from a HO (hidden-order) to AF (antiferromagnetic) ground state. From these critical values and Larmor neutron diffraction, we conclude that the magnetic properties are governed by the shortest U-U distance in the plane (a lattice parameter). Under stress, the orthorhombic unit cell stays centered. A key point shown by this study is the presence of a threshold for the uniaxial stress along the a axis before the appearance of the large AF moment, which indicates no mixture of the order parameter between the HO ground state and the AF one as under hydrostatic pressure. The two most intense longitudinal magnetic excitations at Q{sub 0} =(1,0,0) and Q{sub 1} =(0.6,0,0) were measured in the HO state: the excitation at Q{sub 0} decreases in energy while the excitation at Q{sub 1} increases in energy with the uniaxial stress along the a axis. The decrease of the energy of the excitation at Q{sub 0} seems to indicate a critical energy-gap value of 1.2(1) meV at {sigma}{sub x}{sup a}. A similar value was derived from studies under hydrostatic pressure at p{sub x}.

• OSTI ID: 21596918
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 84, Issue 18; Other Information: DOI: 10.1103/PhysRevB.84.184430; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ANTIFERROMAGNETISM
COMPARATIVE EVALUATIONS
CRITICAL PRESSURE
ENERGY GAP
EXCITATION
GROUND STATES
LATTICE PARAMETERS
MAGNETIC PROPERTIES
NEUTRON DIFFRACTION
ORDER PARAMETERS
ORTHORHOMBIC LATTICES
PRESSURE RANGE GIGA PA
RUTHENIUM COMPOUNDS
SILICON COMPOUNDS
STRESSES
URANIUM COMPOUNDS
ACTINIDE COMPOUNDS
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
DIMENSIONLESS NUMBERS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EVALUATION
MAGNETISM
PHYSICAL PROPERTIES
PRESSURE RANGE
REFRACTORY METAL COMPOUNDS
SCATTERING
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS