Magnetic alignment in nominally non-magnetic hexagonal metal hydrides: NMR

Abstract

Powders of three hexagonal metal-hydrides or -deuterides are found to align in 4.4– 8.3 T magnetic fields used for NMR. The field-alignment is unexpected, since all three systems have very small susceptibilities, as demonstrated by sharp NMR lines. The extent of alignment runs from nearly complete to barely detectable in ZrBe 2(H,D) x , LuD 3, and YD 3, respectively. The preferred alignment direction in ZrBe 2(H,D) x is with the crystallites’ c-axis perpendicular to B, while the c-axis and B tend to be parallel in LuD 3 and YD 3. The susceptibilities χ || and χ ⊥ are determined from bulk magnetization measurements in aligned ZrBe 2H 1.4 powder. The alignment must be considered for proper analysis of NMR spectra in these and related materials.