Nuclear-spin diffusion in(NH4)2SnBr6
| Autor: | E.E. Ylinen, L.P. Ingman, Marko Patrick John Punkkinen |
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| Rok vydání: | 1982 |
| Předmět: | |
| Zdroj: | Physical Review B. 26:3943-3945 |
| ISSN: | 0163-1829 |
| DOI: | 10.1103/physrevb.26.3943 |
| Popis: | Nuclear-spin diffusion between the protons of the $A$ and $T$ species N${\mathrm{H}}_{4}^{+}$ ions in an ${(\mathrm{N}{\mathrm{H}}_{4})}_{2}$Sn${\mathrm{Br}}_{6}$ single crystal is studied by the rf pulse sequence $90\ifmmode^\circ\else\textdegree\fi{}\ensuremath{-}{t}_{1}\ensuremath{-}{90\ifmmode^\circ\else\textdegree\fi{}}_{180\ifmmode^\circ\else\textdegree\fi{}}\ensuremath{-}{t}_{2}\ensuremath{-}90\ifmmode^\circ\else\textdegree\fi{}$. The shape of the induction signal after the third pulse approaches the equilibrium shape during the variable time ${t}_{2}$ at a speed characterized by the spin-diffusion time constant ${T}_{\mathrm{SD}}$. ${T}_{\mathrm{SD}}$ is longest for ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{B}}}_{0}\ensuremath{\parallel}[111]$ and shortest for ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{B}}}_{0}\ensuremath{\parallel}[100]$ below 30 K. It varies with temperature. |
| Databáze: | OpenAIRE |
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