ラウエ帯

Laue zone

入射線の方向に垂直な逆格子面(逆格子点によって作られる面)をラウエ帯という。原点(入射点である逆格子点)を含むラウエ帯をゼロ次ラウエ帯(ZOLZ)と呼び、入射線の向きと反対方向に原点から数えてn番目のラウエ帯をｎ次ラウエ帯と呼ぶ。回折図形はエワルド球によるラウエ帯上の逆格子点の切り口と表せる。同じラウエ帯に属する逆格子点は回折図形に円環状または弧状に表れる。より高次のラウエ帯(HOLZ)になるほどその円弧の半径が大きくなる。

Laue zones are defined as the reciprocal lattice planes perpendicular to the direction of the incident beam. The Laue zone containing the origin (reciprocal lattice point corresponding to the incidence point) is called the zeroth-order Laue zone, and Laue zones of the n-th-order counted from the origin to the opposite direction of the incident beam are called the n-th-order Laue zones. The diffraction pattern is considered as the section of the reciprocal lattice points on the Laue zones cut by the Ewald sphere. The reciprocal lattice points belonging to the same Laue zone appear in a circular or an arc form in a diffraction pattern. The radius of the circle or arc is larger for higher-order Laue zones.