Institute of Applied Beam Science, Ibaraki University, Mito 310-8512, Japan.
Phys Rev Lett. 2013 May 24;110(21):216406. doi: 10.1103/PhysRevLett.110.216406. Epub 2013 May 23.
We report neutron diffraction measurements on U(Ru(0.96)Rh(0.04))(2)Si(2) single crystal under pulsed high magnetic fields up to 30 T applied along the tetragonal c axis. The high-field experiments revealed that the field-induced phase II above 26 T corresponds to a commensurate up-up-down ferrimagnetic structure characterized by the wave vector q=(2/3,0,0) with the magnetic moments parallel to the c axis, which naturally explains the one-third magnetization plateau and the substantially changed Fermi surface in phase II. This a-axis modulated magnetic structure indicates that the phase II near the hidden order phase is closely related to the characteristic incommensurate magnetic fluctuations at Q(1)=(0.6,0,0) in the pure system URu(2)Si(2), in contrast to the pressure-induced antiferromagnetic order at Q(0)=(1,0,0).
我们报道了在脉冲高磁场下对 U(Ru(0.96)Rh(0.04))(2)Si(2) 单晶进行的中子衍射测量，磁场高达 30 T，沿四方 c 轴施加。高场实验表明，在 26 T 以上的场诱导相 II 对应于一个共格的 up-up-down 铁磁共振结构，其波矢 q=(2/3,0,0)，磁矩平行于 c 轴，这自然解释了三分之一的磁化平台和相 II 中明显变化的费米面。这种 a 轴调制的磁结构表明，在近隐藏序相的相 II 与纯系统 URu(2)Si(2)中在 Q(1)=(0.6,0,0)处的特征非共格磁涨落密切相关，而与压力诱导的在 Q(0)=(1,0,0)处的反铁磁有序相反。
