How did barium titanate particulates stick together in the nebula

It was suggested by Tanaka and others that there may be Ba-rich micro-components in the Allende meteorite (Geochem. J. 10 : 111 (1976)). The present authors state that they have confirmed this suggestion by discovery of Ba-rich particulates, the distribution of which in the matrix of the Allende is shown electron photographically. Each of the apparent particles seems to be composed of finer particulates probably of submicron size. It was also found that the Ba-rich spots are also high in Ti content. Electron microprobe studies showed the atomic ratio of Ba to Ti to be almost 1:1. The contents of Ba0 and Ti02 in most Ba-Ti-rich portions were 59% and 34% respectively, compared with the theoretical values 66% and 34% for pure BaTi03. Thus the purity of the micro-component as barium titanate is very high. The Ba content of the Allende BaTi03 is up to 1.7 x 105 times the corresponding chondritic abundance. It is stated to be difficult to see how the BaTi03 particles could selectively stick to each other in nebula, but it may be conceivable that some special factor was operative. Here some unique electrical properties of BaTi03 that may be directly associated with the formation of the particulates are discussed. (U.K.)