The effect of radiation damage on micro-mechanical properties of Bi4Ge3O12 single crystal

✍ Scribed by Hong Wang; Haohong Chen; Jiayue Xu; Guanqin Hu; Jingtai Zhao

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 579 KB
• Volume: 631
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2010.12.039

✦ Synopsis

In this work, bismuth germanate (Bi 4 Ge 3 O 12 or BGO) crystals were grown by vertical Bridgmen method, and the micro-mechanical properties of BGO crystal before and after ultraviolet irradiation (UV-irradiation) were systematically investigated using micro-indentation technique and discussed combining with the optical properties. The results suggested that BGO crystal exhibited significant changes of the optical properties before and after UV-irradiation, showing obvious radiation damage. After UV-irradiation, the colorless and transparent BGO crystal turned to be light brown, and the optical transmittance at 350 and 480 nm were cut down about 12.6% and 5.83%, respectively. The peak of thermoluminescence curve of the irradiated BGO crystal was much stronger than that of the nonirradiated sample, implying the apparent increase of the concentration of color centers. Furthermore, it was found that the Vickers' micro-hardness H v increased about 5.44% from 533 to 562 kg mm À 1/2 , the fracture toughness K c decreased about 6.53% from 0.674 to 0.630 MPa m 1/2 , which showed that BGO crystal became little ''hard and brittle'' as a result of radiation damage.