A static and “magic-angle” sample-spinning nuclear magnetic resonance spectroscopic study of 11B in Si[B]. An analysis of spin—spin and spin—lattice relaxation behavior in the metallic state

✍ Scribed by Jürgen Haase; Eric Oldfield; Kirk Schmitt

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 680 KB
• Volume: 193
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)85667-y

✦ Synopsis

We have investigated the signal intensity, lineshape, spin-lattice and spin-spin (spin-echo decay) relaxation behavior of "B nuclei in a Si [ B] extrinsic semiconductor in the metallic state, as a function of magnetic field strength and temperature. We find that essentially all boron spins are in a highly symmetric environment, characterized by a mean nuclear quadrupole coupling constant (e2qQ/h) of z 12 kHz. The spin-lattice relaxation is Korringa like, with a T, TX 550 s K, at both 5 and 300 K, indicating a mean Knight shift of x 70 ppm. The spin-spin relaxation time, T zE, is 25 ms at 8.45 T, independent of temperature, or magnetic field strength in the range 2.35 to 11.7 T, at 300 K. The T2e value is in good agreement with the predictions of a model of homonuclear dipolar interactions within metallic Si [ B] clusters.