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I am currently studying Ultrasonic transducers – Materials and design for sensors, actuators and medical applications by Kentaro Nakamura. In chapter 1.2.1 Ferroelectricity, the author says the following:

$\ce{BaTiO_3}$ is realised as a ceramic, originating as a mouldable paste, which is dried and sintered to form the final material. The properties of the paste result from the mixing of particles with a liquid and its basis in particles leads to a material comprising crystallites or grains tightly bound together, with properties differing between the individual grains and the collection of grains in the bulk ceramic because of the effects of the interfaces between the grains. Following the principle of minimisation of energy, and taking into account the resulting internal dynamics of the relative positions of the ions, $\ce{BaTiO_3}$ divides itself into multiple domains within each grain, each domain having a common polarisation, but with the polarisation differing in direction from that of neighbouring domains by either $90^\circ$ or $180^\circ$.

My concern is with this part:

The properties of the paste result from the mixing of particles with a liquid and its basis in particles leads to a material comprising crystallites or grains tightly bound together, with properties differing between the individual grains and the collection of grains in the bulk ceramic because of the effects of the interfaces between the grains.

What is meant by "basis" in "... its basis in particles leads to a material comprising crystallites or grains tightly bound together, ..."? I don't understand what this means. Is this possibly a typo or incorrectly used term by a non-native English speaker? If so, then does anyone know what they meant (or what it should say for this described process)?

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  • $\begingroup$ I would suggest that "basis" can be here replaced by "content" $\endgroup$ – Maurice Dec 14 '20 at 10:10
  • $\begingroup$ @Maurice In that case, what would "The properties of the paste result from the mixing of particles with a liquid and its content in particles leads to a material comprising crystallites or grains tightly bound together, ..." mean? I still don't understand what "content in particles" would mean. $\endgroup$ – The Pointer Dec 14 '20 at 10:12
  • $\begingroup$ It may mean that mixing a liquid with a powder makes a paste which is heterogeneous on the microscopic level. But this mixture may appear homogeneous at the observer. If you imagine the mud made by sand deposited in the bottom of a lake, you may have an idea of this substance. Mud is made of sand grains with water between them. The liquid may be considered as having a ¨basis¨ or a "content" of sand $\endgroup$ – Maurice Dec 14 '20 at 10:47
  • $\begingroup$ @Maurice Hmm, I see what you mean. But, in the mud example, the water is not in the sand particles, it's between them, right? "content in particles" sounds weird. But your explanation makes sense, so perhaps that's what the author meant. $\endgroup$ – The Pointer Dec 14 '20 at 10:50
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    $\begingroup$ Of course. The water is not in the sand but between the grains. $\endgroup$ – Maurice Dec 14 '20 at 11:01
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The author is attempting to indicate that the "paste" is a suspension of particles that aggregate as it dries (ie the liquid portion evaporates), in contrast to a solution of a dissolved solid that recrystallizes as the solvent evaporates. Because the particles never dissolve, there is no possibility for a single crystal to form that is any larger than an already existing particle. Therefore, the resulting solid is necessarily composed of many small crystals/particles with boundary zones between them, rather than having a large scale uniform structure.

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