Crystallochemical relationship is one whereby the main structural features act as exhaustive aspects on the similar basis as the closely-related composition of chemicals. It is extremely important to have an understanding of the crystallochemical relationship between structures and temperature as having knowledge of it leads to a perfection in the structures formation. This is especially so as the structural parameters of FePO4 falls very closely to the values that are limited i.e. too high a pressure causing instability in the thermal conditions, thus it is in even greater importance that the amount of temperature used is studied in detail since it is a determinant of thermal stability of the parameters of the present structure. …show more content…
For example, the low temperature in an alpha phase inclines to that of the values collected by the beta-quartz-type FePO4 which uses high temperature. However, FePO4 at high temperatures has also its own limits, such as its cell parameters can face difficulties in its measurement. On the other hand, the other structures and beta forms face no issue and no limits. Another distinct difference spotted between the alpha and beta form is that quartz homeotypes can be converted into the beta form in the prevalence of high temperature but it cannot be said the same for alpha form. In other words, quartz homeotypes do not convert into alpha form. This is because the alpha form experiences a setting that has very, very high temperature and upon its recovery, it is still unlikely to be able to display enough thermal stability to allow such a transition. Thus, we study the crystallochemical relationship between the structures and dependent temperature to understand the different characteristics of structures which …show more content…
Tetrahedral tilting can also cause a deformation, and hence have to be taken in caution. In this case, the tetrahedral tilting mentioned in the reading is largely explained by the increase in the number of atoms FE-O-P bridging angles that causes a substantial decline in its angles as temperature reaches to a high of 980 K. Through this, the first alpha and beta phase transition is approached and verged upon. This transition continues to effect important and critical discontinuities in the structures. Discontinuities generally refers to the state of disconnectedness, and in this particular concept used here, it means that there is a prevalent gap and lack of continuity in the structure. The relationship in which the temperature has with these structures of the FePO4 polymorphs are displayed through the thermal expansion that starts out in the initial alpha phase. First of all, this expansion is solidly non-linear and is prevailed by the present angular variations. As for the beta phase, due to the lack of mechanism, there is absolutely no thermal expansion at all. Hence, it can also be said that a dynamic instability only exists in the alpha FePO4 and not in the beta FePO4. In addition, there is an occurrence of diffraction, meaning a mild bending of the structure, in the inter-conversion of alpha FePO4 and B-FEPO4 through tetrahedral tilting. FePO4 is