Pulsed Nuclear Magnetic Resonance on 3He Adsorbed on Bare and 4He Preplated MCM-41 Using DC SQUID Detection

We report low field DC SQUID NMR measurements down to 1.5 K of 3He adsorbed in the pores of the mesoporous molecular sieve MCM-41. In the first experiment measurements were made on 3He adsorbed onto the bare pore walls of MCM-41 with coverages ranging from \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$n_{^{3}\mathrm{He}}=0.86n_{1}$\end{document} to full pores at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$n_{^{3}\mathrm{He}}=1.79n_{1}$\end{document} , where n1 is the coverage for monolayer completion. A second experiment was performed with low 3He coverages ( \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$n_{^{3}\mathrm{He}}\sim0.01n_{1}$\end{document} ) on 4He preplated pores, where a crossover to a quasi-1D state is expected to occur at temperatures sufficiently below 700 mK.