Field of primary crystallization

When the system attains the eutectic temperature the solid phase B also starts to crystallize. At the eutectic temperature, the system has no degree of freedom (A = 2, / = 3, V = 0) and its cooling will stop. The system maintains the eutectic temperature until its total solidification. In the field of primary crystallization of the component B, the crystallization proceeds like in the simple eutectic system. 

From liquidus projection, it is known that two ternary phases with composition of YNi2C2, probably, Y5Ni29C3 are present in this system. YNi2C2 melts congruently and has a large field of primary crystallization from the melt, and the phase with a probable composition YjNi29C3 is located between the fields of primary Y2Nij7 and... 

By the method of thermal analysis [1927Kas] first constructed the liquidus surface of the system. It involves two fields of primary crystallization of the phases (6Fe) and (aCo,"yFe,Ni), divided by the monovariant peri-tectic type curve pip2 of the joint crystallization. The temperature decreases fi om the Fe-Ni towards the CoFe binary. 

Nd2Te3-Te. The liquidus of the system consists of the 18 fields of primary crystallization, the field NdTe being the largest one. The monovariant curves intersect in 18 non-variant points, 6 of them being eutectic and 12 being peritectic. 

A sample in the primary crystallization field of phase C will behave differently during crystallization. Here phase C precipitates with composition identical to C (no solid solubility) during cooling keeping the A B ratio in the melt constant until the melt hits the intersection of the two primary crystallization fields. At this temperature a will start to precipitate together with further C and from this point on the cooling process corresponds to that observed for the sample with overall composition P after this sample reaches the same stage of the crystallization path. 

The advent of the FFC instruments has opened a number of important application areas (molecular dynamics of liquid crystals, paramagnetic contrast MRI agents, proteins, polymers, etc.) and has thus provided a powerful impulse for further development of variable-field NMR relaxometry. Since 1996, Stelar entered the field and, building on the Noack-Schweikert technology (67), started producing the first commercial FFC NMR relaxometers. The availability of such instruments has further enhanced the drive towards new applications, apart from confirming the enormous potential of the technique as a primary tool for the study of molecular dynamics of even quite complex systems. 

Let us now consider the crystallization process operating on a composition C2, initially poorer in component 1 this composition falls into the compositional triangle C -2-3. Crystallization begins in primary phase field y" (T = 1225 °C). Precipitation of y" crystals drives the residual liquid radially away from C2 along direction 2-C2. At T = 1100 °C, the composition of the liquid reaches cotectic line Ejii-P, where crystals y " begin to form together with y". At peritectic point P, crystals y" are partially resorbed by reaction with the liquid to form intermediate compound C . However, the peritectic reaction is not completed, because of ex-... 

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