27Al NMR study in ZrNiAl.
We have studied the microscopic properties of the hexagonal ZrNiAl, a model compound for a wide family of intermetallic compounds crystallizing in this type of structure, by using 27Al NMR spectroscopy. We have investigated the lineshape of static and MAS NMR spectra as a function of magnetic field strength (4.7-9.4 T) and temperature (5-300 K). Our data indicate that the 27Al NMR spectra result from a combined effect of quadrupole and anisotropic shift interactions. The 27Al nuclei are in an environment characterized by the quadrupole coupling constant e2qQ/h of 3.3 MHz, asymmetry parameter etaQ of 0.42, isotropic shift delta(iso) of 393 ppm, shift anisotropy delta(anis) = delta(zz) - (delta(xx) + delta(yy))/2 of 150 ppm, and asymmetry factor etaS of 0.5. They are found to be temperature independent. The spin-lattice relaxation rate measured at 7.05 T is proportional to the temperature with T1T = 135 s K. The mechanisms responsible for observed values of delta(iso), delta(anis), T1T, and the enhanced Korringa constant are discussed.
W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wrocław. bnowak@int.pan.wroc.pl
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Nowak
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Hayashi
D000535:Aluminum / Q000737:chemistry*; D016880:Anisotropy; D009682:Magnetic Resonance Spectroscopy; D009532:Nickel / Q000737:chemistry*; D011868:Radioisotopes; D013057:Spectrum Analysis; D015040:Zirconium / Q000737:chemistry*
D011868:Radioisotopes; C433593:ZrNiAl; D009532:Nickel; D015040:Zirconium; D000535:Aluminum