Bahadur H
Nat. Phys. Lab., New Delhi.
IEEE Trans Ultrason Ferroelectr Freq Control. 1994;41(6):820-33. doi: 10.1109/58.330263.
A study of electrodiffusion (sweeping) and irradiation effects on hydroxyl defects has been carried out on good quality optically clear natural quartz crystals. The crystals were of Arkansas and Brazilian origin which are used as starting material in hydrothermal synthesis of high purity cultured quartz crystals. In particular, various OH(- ) related point defects have been monitored using infrared absorption measurements in the 3100-3700 cm(-1) range. Our estimates from sweeping and irradiation results show that the Brazilian crystal had a much higher concentration of hydrogen than the Arkansas crystal. We have therefore designated the Brazilian crystal as "high-H" and Arkansas stone as "low-H" quartz. High- and low-H samples of natural quartz in three different conditions, unswept, Na-swept, and H-swept, were subjected to a sequence of low- and room-temperature irradiations that separate proton and alkali motion. Irradiation at 77 K reduces the strength of almost all the IR bands except the short-bond Al-OH(-) center. Warm up to room temperature results in significant recovery (85-95%). Al-OH(-) centers in natural quartz were found to exhibit irradiation characteristics similar to those of cultured quartz. For similar radiation doses (2 Mrad) the prominent bands, Li and H dependent at 3476 cm(-1) (designated as Li-n3a) and Na and H dependent at 3451 cm (-1) (designated as Na-n2a) showed a larger decay at 300 K-irradiation than at 77 K. The prominent H-dependent OH(-) band at 3468 cm(-1) (designated as H-n2a) did not show any depletion of peaks after 300 K-irradiation while the 77 K-irradiation reduced their strength to about 10% of the as-H-swept strength. The results have been discussed in terms of protons and alkali ions motion to shallow and deep traps and compared with cultured quartz.
对优质光学透明天然石英晶体上的电扩散（扫掠）和辐照对羟基缺陷的影响进行了研究。这些晶体来自阿肯色州和巴西，是水热合成高纯度人工培育石英晶体的起始原料。特别地，使用3100 - 3700 cm⁻¹范围内的红外吸收测量来监测各种与OH⁻相关的点缺陷。我们从扫掠和辐照结果得出的估计表明，巴西晶体中的氢浓度比阿肯色晶体高得多。因此，我们将巴西晶体指定为“高H”石英，将阿肯色晶体指定为“低H”石英。天然石英的高H和低H样品在三种不同条件下，即未扫掠、Na扫掠和H扫掠，经受了一系列低温和室温辐照，这些辐照可分离质子和碱金属的运动。77 K下的辐照会降低几乎所有红外波段的强度，但短键Al - OH⁻中心除外。升温至室温会导致显著恢复（85 - 95%）。发现天然石英中的Al - OH⁻中心表现出与人工培育石英相似的辐照特性。对于相似的辐射剂量（2 Mrad），在3476 cm⁻¹处依赖Li和H的突出波段（指定为Li - n3a）以及在3451 cm⁻¹处依赖Na和H的突出波段（指定为Na - n2a）在300 K辐照下比在77 K辐照下表现出更大的衰减。在3468 cm⁻¹处突出的依赖H的OH⁻波段（指定为H - n2a）在300 K辐照后未显示出任何峰值损耗，而77 K辐照将其强度降低至扫掠后强度的约10%。已根据质子和碱金属离子向浅陷阱和深陷阱的运动对结果进行了讨论，并与人工培育石英进行了比较。
