APPLICATION
Laser induced break down(LIBS) is a method of analysis of materials. It?is a kind of emission spectroscopy, very easy to analyse many kinds of elements at the same time. Since it was introduced for analytical field in 1962, especially in these two decades, LIBS has developed very fast. Now it has been researched not only in LABS, but in many field as well, such as metallurgy, cultural heritage and archaeology. Spectrograph also plays important role in LIBS system, despite of laser and fast detectors.
light sources are very popular in many optical experiments, but many can’t provide monochromatic light or a short bandwidth light. Tunable Light Source (TLS) can match these requirements.?It’s very easy to achieve high bright emission light or hight resolution monochromatic light with a diffraction system.
氧 (氮)化物熒光粉材料以其高發(fā)光效率、可被可見(jiàn)光有效激發(fā)、穩(wěn)定性高和環(huán)境友好等諸多優(yōu)點(diǎn),在固體發(fā)光領(lǐng)域受到廣泛重視。其中,稀土摻雜的熒光粉由于表現(xiàn)出較高的發(fā)光強(qiáng)度、較高的量子效率和優(yōu)異的熱穩(wěn)定性,具有較好的應(yīng)用前景。銪(Eu)元素在化合物中存在Eu2+和Eu3+兩種價(jià)態(tài)。Eu2+發(fā)射峰位易受晶體場(chǎng)影響的,即基體或者參雜材料的改變(濃度、元素等),發(fā)射峰的強(qiáng)度會(huì)發(fā)生變化,發(fā)射中心會(huì)發(fā)生紅移或者藍(lán)移;Eu3+的發(fā)射峰是由其自身決定的,比較尖銳、峰位不受晶體場(chǎng)的影響。
鈣鈦礦(Perovskite)材料是一類有著與鈦酸鈣(CaTiO3)相同晶體結(jié)構(gòu)的材料。 鈣鈦礦材料結(jié)構(gòu)式一般為ABX3,其中A,B是兩種陽(yáng)離子,X 是陰離子。 近200年來(lái),人們對(duì)鈣鈦礦材料的研究從未停止,元素周期表幾乎所有的元素都可以占據(jù)晶格結(jié)構(gòu)的位置組成鈣鈦礦。鈣鈦礦大家族里現(xiàn)已包括數(shù)百種物質(zhì),范圍極為廣泛,其中很多是人工合成的。 這類材料具有獨(dú)特的魅力,其多變的晶體結(jié)構(gòu)可以引申出眾多的材料屬性:可以是絕緣體、半導(dǎo)體、導(dǎo)體、超導(dǎo)體,可以具有鐵電性、鐵磁性,鐵彈性、催化性、質(zhì)子傳導(dǎo)性、離子傳導(dǎo)性、光電性。
概念解釋:暗場(chǎng)顯微(英文:Dark-field microscopy)或稱暗視野顯微(英文:Dark ground microscopy)描述光學(xué)顯微和電子顯微中的一種特殊顯微手法,除去觀測(cè)物體以外的光線或電子進(jìn)入物鏡,使目鏡中觀測(cè)到的視野背景是黑的,只有物體的邊緣是亮的。利用這個(gè)方法能見(jiàn)到小至 4~200nm的微粒子,分辨率可比普通顯微法高50倍。