title: Temperature-dependent 29Si NMR resonance shifts in lightly- and heavily-doped Si:P.
abstract: Careful NMR measurements on a very lightly-doped reference silicon sample provide a convenient highly precise and accurate secondary chemical shift reference standard for (29)Si MAS-NMR applicable over a wide temperature range. The linear temperature-dependence of the (29)Si chemical shift measured in this sample is used to refine an earlier presentation of the paramagnetic (high-frequency) (29)Si resonance shifts in heavily-doped n-type silicon samples near the metal-nonmetal transition. The data show systematic decreases of the local magnetic fields with increasing temperature in the range 100-470 K for all samples in the carrier concentration range from 2×10(18) cm(-3) to 8×10(19) cm(-3). This trend is qualitatively similar to that previously observed for the two-orders of magnitude larger (31)P impurity NMR resonance shifts in the same temperature and concentration ranges. The (29)Si and (31)P resonance shifts are not related by a simple scaling factor, however, indicating that impurity and host nuclei are affected by different subsets of partially-localized extrinsic electrons at all temperatures.
authors.affiliation: Department of Physics, Oregon State University, Corvallis, OR 97331-6501, USA.
authors.forename: Ernesta M
authors.initials: EM
authors.lastname: Meintjes
authors.forename: William W
authors.initials: WW
authors.lastname: Warren
authors.forename: James P
authors.initials: JP
authors.lastname: Yesinowski
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010758:Phosphorus / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013696:Temperature
chemical_list: D010758:Phosphorus; D012825:Silicon
keywords: (29)Si MAS-NMR; Chemical shift; Dopant; Knight shift; Metal–nonmetal; Semiconductor; Silicon; Temperature dependence