NMR study of molecular reorientations in NH4H2AsO4

✍ Scribed by R. Grosescu

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 231 KB
• Volume: 21
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(73)80019-3

✦ Synopsis

Zeeman ( (T_{1 Z}) ) and dipular ( (T_{1}) ) spin-latice relaxation times of proicns in (\mathrm{NH}{4} \mathrm{H}{2} \mathrm{AsO}{4}) were measured as a function of temperature The evistence of a slow motion (\left(\tau \approx 10^{-3}\right.) sec) is sstablished, which is niost probably a low frequency hindered reorientation of (\mathrm{H}{2} \mathrm{AsO}{4}) groups This motion is slowed down below the Curse point (T{\mathrm{c}}) A sharp increase of the dipolar relasation rate above (T=314^{\circ} \mathrm{K}) indicates the possiolity of a new hugh temperature plase transition in this compound