Effect of Pressure on Tiny Antiferromagnetic Moment in the Heavy-Electron CompoundURu2Si2

Abstract

Effects of pressure on tiny antiferromagnetic moments in the heavy-electron compound URu2Si2 Amitsuka, H.; Sato, M.; Metoki, N.; Yokoyama, M.; Kuwahara, K.; Sakakibara, T.; Morimoto, H.; Kawarazaki, S.; Miyako, Y.; Mydosh, J.A.

High purity specimens of URu2Si2produced by a molten metal flux technique

“…Furthermore, a variety of studies have shown that magnetism is found on the border of the hidden order state. For instance, measurements under applied pressure show that at P c ≈ 0.5 GPa, there is a first-order phase transition from hidden order to conventional antiferromagnetism, which is accompanied by destruction of the superconductivity [12][13][14]. Similar behaviour is observed with chemical pressure in the substitution series URu 2−x Fe x Si 2 [15].…”

Competition between hidden order and antiferromagnetism inURu2Si2under uniaxial stress studied by neutron scattering

“…7,8 This implies that there is an implicit and common parameter leading to an equivalent effect in the different types of compression. In this subsection, we discuss the crystal strains caused by P and σ, and propose that the c/a ratio plays an important role in the competition between the two ordered phases.…”

“…We found from the neutron scattering experiments that µ o is strongly enhanced by applying pressure from 0.017 µ B /U (P = 0) to 0.25 µ B /U (P = 1.0 GPa). 7,8 In parallel, the 29 Si-NMR study revealed that the system is spatially separated into two differently ordered regions below T o : one is AF with a large moment and the other is non-magnetic. 9,10 The AF volume fraction is found to increase with P , roughly in proportion to µ 2 o (P ), while the magnitude of internal field is almost independent of P .…”

Tuning of Hidden Order and Superconductivity in URu2Si2 by Applied Pressure and Re Substitution

“…More recently, it was found that non-Fermi liquid behavior, often associated with a quantum critical point, at which an ordering temperature is driven to 0 K, persists well into the ferromagnetic ordered phase that exists at moderate Re concentration in URu 2-x Re x Si 2 , a very unusual occurrence [10]. Early pressure studies on URu 2 Si 2 showed that applied pressure suppresses superconductivity, while the HO/AFM transition temperature is increased [11] and the measured moment grows substantially [12]. However, there still exist disagreements about the relationship between HO, AFM, and superconductivity as well as the general temperature-pressure phase diagram [12][13][14][15][16].…”

“…Early pressure studies on URu 2 Si 2 showed that applied pressure suppresses superconductivity, while the HO/AFM transition temperature is increased [11] and the measured moment grows substantially [12]. However, there still exist disagreements about the relationship between HO, AFM, and superconductivity as well as the general temperature-pressure phase diagram [12][13][14][15][16]. To more precisely map the pressure dependence of the hidden order and superconducting phases, electrical resistivity measurements on single crystals of URu 2 Si 2 are being performed as a function of temperature, magnetic field, and pressure.…”