Materials Research Department, Risø National Laboratory, PO Box 49, DK-4000 Roskilde, Denmark.
J Microsc. 1999 Sep;195(3):204-211. doi: 10.1046/j.1365-2818.1999.00581.x.
Precise knowledge of the position of the source point is a requirement if electron backscattering patterns (EBSPs) are to be used for crystal orientation measurements or other types of measurements which demand a geometrical analysis of the patterns. Today, possibly the most popular method for locating the source point is a computational technique which uses the positions of a number of indexed Kikuchi bands for calculating the coordinates of the point. A serious limitation of this calibration technique is, however, that the localized bands must first be indexed, which is difficult if the location of the source point is not known with reasonable precision. This paper describes a new technique which determines the location of the source point from the positions of a number of bands in an arbitrary EBSP. Besides the positions of the Kikuchi bands, the only information which is required by this new calibration procedure is the same crystallographic information which is used for normal indexing of EBSPs. The procedure is shown to work successfully with patterns from a simple cubic crystal, as well as with patterns from an orthorhombic BiSCCO superconductor. In the former case, four bands are shown to be sufficient to ensure a unique determination of the source point, whereas five bands are required in the latter case. Once the bands have been localized, the time required for calculating the source point position is of the order of 1 min on a standard PC.
如果要将电子背散射图案（EBSP）用于晶体取向测量或其他需要对图案进行几何分析的测量类型，那么精确了解源点的位置是一项必要条件。如今，可能最常用的定位源点的方法是一种计算技术，该技术利用多个已标定指数的菊池带的位置来计算该点的坐标。然而，这种校准技术的一个严重局限是，必须先对局部化的带进行标定指数，如果源点的位置没有合理的精度就很难做到。本文描述了一种新技术，它能从任意EBSP中多个带的位置确定源点的位置。除了菊池带的位置，这种新校准程序所需的唯一信息就是用于EBSP常规标定指数的相同晶体学信息。结果表明，该程序对简单立方晶体的图案以及正交晶系BiSCCO超导体的图案都能成功起作用。在前一种情况下，四条带就足以确保唯一确定源点，而在后一种情况下则需要五条带。一旦带被局部化，在标准个人电脑上计算源点位置所需的时间约为1分钟。
