Magnetic field and temperature dependence of x-ray superlattice intensity in multipole ordered phase of Pr(Ru_1-xRh_x) ₄P₁₂ (x = 0, 0.03)

Superlattice reflections in the multipole ordered phase of PrRu ₄P₁₂ and Pr(Ru_0.97Rh_0.03) ₄P₁₂ has been measured using a synchrotron x-ray scattering technique. The Thomson scattering intensity of (111) at 1.7 K does not show significant variation with magnetic field up to 7 T in contrast to the reported variation of electrical resistivity. This means that the lattice distortion in the ordered phase is robust and the staggered ordering remains after split of triplet ground state at half of Pr sites. The nonmetallic staggered ordering is not destroyed completely by applying magnetic field. Energy scan at (111) reflection of Pr(Ru_0.97Rh_0.03) ₄P₁₂ show temperature dependence around resonant energy of Pr L₃ edge. This may allow us to observe anisotropy of electronic ordering of Pr sites and gives us a hint for direct observation of higher rank multipole order in PrRu₄P₁₂.