The ¹¹B Nuclear Magnetic Resonance in CeB₆ Single Crystal

Abstract

NMR measurements were performed on the 11 B in CeB 6 single crystal below 4.2 K and at 77 K using the spin echo technique. The frequency was fixed mostly at 10.7 MHz and the external magnetic field was parallel to the (110) plane. The spectrum at 4.2 K was explained by taking into account the dipolar fields from ferromagnetic moments on Ce atoms. The spectrum in the [111] direction splits into two lines below 3.55 ±0.05 K, which is interpreted tentatively by the occurence of the G-type antiferromagnetic ordering with magnetic moments parallel to the external field and with the maximum component 0.1 µ B /Co around 2.4 K. The Knight shift for the [111] direction increases with decreasing temperature from +0.49 ±0.06% at 4.2 K to +2.02 ±0.25% at 1.4 K. The angular dependence of the spectrum at 2.6 K was explained to some extent by assuming the G-type and ferromagnetic components of magnetic moments. However, the spectrum at 1.8 K could not be explained by those components.