Jakovac I, Horvatić M, Schwier E F, Prokofiev A, Paschen S, Mitamura H, Sakakibara T, Grbić M S
Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, Zagreb HR 10000, Croatia.
J Phys Condens Matter. 2020 Jun 3;32(24):245601. doi: 10.1088/1361-648X/ab70c4.
We report Pd nuclear magnetic resonance (NMR) and nuclear quadrupolar resonance (NQR) measurements on a single crystal of CePdSi, where antiferroquadrupolar and antiferromagnetic orders develop at low temperature. From the analysis of NQR and NMR spectra, we have determined the electric field gradient (EFG) tensors and the anisotropic Knight shift (K) components for both inequivalent Pd sites-Pd(32f) and Pd(48h). The observed EFG values are in excellent agreement with our state-of-the-art density functional theory calculations. The principal values of the quadrupolar coupling are [Formula: see text] MHz and [Formula: see text] MHz, for the Pd(32f) and Pd(48h) sites, respectively, which is large compared to the Larmor frequency defined by the gyromagnetic constant [Formula: see text] MHz/T for Pd. Therefore, the complete knowledge of K and the EFG tensors is crucial to establish the correspondence between NMR spectra and crystallographic sites, which is needed for a complete analysis of the magnetic structure, static spin susceptibility, and the spin-lattice relaxation rate data and a better understanding of the groundstate of CePdSi.
我们报道了对CePdSi单晶进行的钯核磁共振（NMR）和核四极共振（NQR）测量，其中反铁四极和反铁磁有序在低温下出现。通过对NQR和NMR谱的分析，我们确定了不等价钯位点——Pd(32f)和Pd(48h)的电场梯度（EFG）张量以及各向异性奈特位移（K）分量。观测到的EFG值与我们最新的密度泛函理论计算结果高度吻合。对于Pd(32f)和Pd(48h)位点，四极耦合的主值分别为[公式：见原文]兆赫兹和[公式：见原文]兆赫兹，与由钯的旋磁常数[公式：见原文]兆赫兹/特斯拉定义的拉莫尔频率相比很大。因此，完整了解K和EFG张量对于建立NMR谱与晶体学位点之间的对应关系至关重要，这对于全面分析磁结构、静态自旋磁化率以及自旋 - 晶格弛豫率数据并更好地理解CePdSi的基态是必要的。
