X射线衍射仪 Detector 扫描方式 Receiving slit Soller slit ▣偶合扫描 Monochromator 26 Anti scatter slit √0-20 D X-ray tube Soller slits (line focus) √0-0 Sample Divergence slit Measuring circle Detector Mon chromator Divergence slit Antiscatter slit F D Detector 0 生0 X-ray slit source Sample
X射线衍射仪 扫描方式 偶合扫描 θ -2θ θ -θ
0-0连动 0 20
X射线衍射仪 扫描方式 ▣偶合扫描 √0-20 √0-0 is 衍射线来源于平行于样品表面(hk)晶面
X射线衍射仪 扫描方式 偶合扫描 θ -2θ θ -θ 衍射线来源于平行于样品表面(hkl)晶面
X射线衍射仪 扫描方式 ▣非偶合扫描 √扫描 180°-20 180°-20 入射X射线和探测器固定 √20扫描 入射X射线和试样固定 衍射X光束 20 入射X光束 a<1°（典型的）
X射线衍射仪
探测器 ·正比(proportional)计数器 ·闪烁(scintillation)计数器(Nal) o 固体探测器(Si(Li) Efficiency,linearity,proportionality and resolution Property/ Linearity loss at Proportionality Resolution Energy per No.of Detector 40,000cpsa for Cu Ko event (eV) eventsb Scintillation <1% Very good 45% 350 23 Proportional <5% Good,but fails at high 14% 26 310 photon flux Solid state Up to 50% Pileup in mid-range 2% 3.7 2,200
探测器 • 正比(proportional)计数器 • 闪烁(scintillation)计数器(NaI) • 固体探测器(Si(Li)) • Efficiency, linearity, proportionality and resolution