MgO在Mg-hBN体系中对合成cBN晶体的影响

 以金属镁粉为触媒，以六角氮化硼为原料，其中加入适量比例的氧化镁，在国产六面顶压机上，在约5.0 GPa压力、1 500～1 800 K温度条件下，合成出了颜色均匀、晶形完整的黄色立方氮化硼单晶体。实验结果表明，在Mg-hBN体系中，氧化镁对合成cBN晶体的颜色及合成温度有很大的影响。     

硅在cBN单晶合成中的行为

 实验制备了复合氮化物Li₈SiN₄，并对合成温度、合成时间、气流量等因素的影响以及产物的稳定性进行了讨论。研究了Li₈SiN₄作为触媒添加剂时硅在cBN单晶合成中的作用。结果表明：cBN晶体多为截角八面体，晶面致密光滑；硅参与cBN的合成反应，并以SiO₂的形式沉积在cBN表面。     

高压合成立方氮化硼的振动光谱

 本文利用FT-IR和Raman光谱对用不同触媒高压合成的不同颜色立方氮化硼晶格振动的声子吸收和散射进行了研究。获得了较完整的晶格振动信息，并在1 000~1 300 cm^-1范围内，观测到了3个新的振动谱带，其中一个位于1 089 cm^-1， 归属为体TO声子和表面TO声子组合带，另两条513、801 cm^-1推测为杂质诱发吸收带。     

Study on measurement of linear electro-optic coefficient of a minute irregular octahedron cBN wafer

The cubic boron nitride (cBN) is a kind of artificial electro-optic (EO) crystal, and we have not found any relative reports so far. Because the artificial synthetic cBN wafers are very small and hard, the wafers cannot be cut into rectangular slabs. The polarizer-sample-λ/4 retardation plate (compensator)-analyzer (PSCA) transverse EO modulator has to be adjusted to the minute irregular octahedron of cBN wafers. When the applied voltage is along [1 1 1] direction of the wafer, due to refraction, the angle between the incident beam direction and the (1 1 1) plane (top or bottom plane) of the wafer should be 25.4°, and the angle between the polarization direction of the polarizer and the plane of incidence should be 50.8° by calculation, respectively. The half-wave voltage of the cBN sample was obtained for the first time, by means of detection of the output optic signals from the modulator with and without an applied electric field on the sample, respectively. Furthermore, the linear EO coefficient was obtained, . The analysis of the experimental resulting error was carried out.     

Kinetics of phase transformation from hBN to cBN in the presence of Mg3BN3 catalyst

Abstract

Transformation kinetics from hBN to cBN has been studied at 6 GPa with changing reaction temperature and content of catalyst mixed with hBN powder. At lower catalyst content (3–10 wt %), rate of transformation was extraordinary rapid between 1300 and 1350 C. At higher catalyst content (30–50 wt %), rate of transformation was decreased. Normal nucleation kinetics was observed at about 1500 C. The rapid transformation temperature region correlates characteristic behavior of the sintering process.     

不同六方氮化硼向立方氮化硼的转化行为

 利用X射线衍射法分析了7种六方氮比硼原料的结晶度、晶粒度和晶格常数，研究了高温高压下六方氮比硼（hBN）向立方氮比硼（cBN）的转化行为和转化率。结果表明，结晶度高和晶粒度细的六方氮化硼易于转化，有利于cBN的成核。     

An isotope separator implantation terminal for the preparation of particle detectors

An implantation terminal for the preparation of p-n junction particle detectors was set up on a multipurpose isotope separator. To provide for homogeneous implantation. the ion beam is swept in the horizontal direction and the samples are moved vertically. In order to be able to implant samples with different geometry two different sample moving systems can be mounted in the implantation chamber. A rotating drum is used for round wafers. a rotating disc in connection with a rotating diaphragm is provided for very elongated samples. Implanted resistive layers on a wafer have resistances which differ by less than ±1 %.     

立方氮化硼单晶-金刚石薄膜异质p-n结

 在Si中掺杂N型片状立方氮化硼单晶的(111)面上,利用热灯丝化学气相沉积方法生长了掺B的p型金刚石薄膜,从而制得了立方氮化硼单晶-金刚石薄膜异质p-n结,测试了该p-n结的V-A特性,结果表明其整流特性良好。     

含氢添加剂对合成cBN的影响及腔体温度分布

 通过对Li基触媒下立方氮化硼的高温高压合成实验结果的分析,研究了在Li基触媒作为主要触媒及氢化物作为添加剂的环境下,立方氮化硼的生长情况。同时由合成后样品中立方氮化硼的生成区域对V型生长区温度梯度分布进行了分析讨论。     

cBN晶体的Raman光谱测量

 用R1000激光共聚焦Raman光谱仪研究了高温高压合成棒中的立方氮化硼（cBN）晶体、原材料六方氮化硼（hBN）和催化剂。Raman光谱测量结果表明：伴随cBN晶体生长的散射峰,出现了两条全新的Raman散射峰（约1.088 cm^-1和约1.368 cm^-1）。该散射峰所对应的物质可能是在高温高压条件下hBN向cBN转变时生成的不完全产物——BN的一种新相。这一结果将有助于进一步讨论cBN的生长机理。