When do we say a crystal that is dissolved into another one is a dopant? Is there any amount limit to name it that or it just should be a solution to specify the solute as a dopant? Infact I'm curious to know does anyone consider an amount boundary between an additive and a dopant in a solid network or it's wrong to think of it that way?
If my memory is not wrong the term dopant was used first in semiconductors where an n or p semiconductor can be obtained depending on the valence of the dopant atom that is added in a very small proportion. In that case dopant refer to a very small amount of a different species that changes the properties of a material dramatically.
A solid solution is whatever homogeneous mixture of elements, by homogeneous different things can be interpreted, it may be a crystalline solid containing different atomic species in the same crystallographic site or an amorphous material that remains homogeneous at some length scale relevant to the properties.
If you mix water and alcohol, they are 100% miscible so you can make a solution 10% water 90% alcohol or 10% alcolhol 90% water. Which is the solvent and the solute is a matter of definition. Solvent is always the majoritary part and solute the minoritary one. In the solid state the same is valid, so a dopant is always a solute.
In the end, it depends on the origin of the name, whether it is originated in the observation of a change of properties or just on the description of a certain state of matter.
Dopant is also used regarding substance abuse, where a small amount of a drug may have an importante physiological efect, in a very similar meaning of dopant in semiconductors...
Looking for those terms in an encyclopedia may do well in this case, without runing the risk of going away from scientific knowledge, since the use of the terms depends on the situation. For example wikipedia is good in describing Dopant and Solid Solution but the relation among those terms is missing...
I think that the word "dopant" in contrary to the word "additive" makes a stress that some applications of the doped material with improved characteristics and functionality exist.
Dear Seyede Farzane Besharat!
Concerning term "dopant" you should take into into accaunt structural and non-structural dopants. If you talk about structural dopants you can call it "solid solution". It doesn't matter much dopant is in your crystal. It just depends on your point of view. In my opinion, term "dopant" is used in case of intetional doping. If it's just a waste in should be called "contominant". But the term "addition" could be used for both cases.
There are some lattices which allow smooth tranthition between them. For example structures CdI2 and NiAs. These structures tipycal for Ti-X (X = S, Se, Te) systems. If you wil start from TiX2 (with structure CdI2) and wil solve Ti finelly you come to TiX (with structure NiAs). And if you wil start from TiX and wil solve X, your solid solution wil based on NiAs lattice. But far away of end points you wil observe a lot of superstructures due to ordering of Ti and vacancies.
So I think that boundary between additive and dopant coinside with boundary of stability superstructures with lattices which are not derivative of end-point structures.
That was so kind of you Mr.Titov and Mr.Nuzhdin. Your answers helped a lot thank you.
Generally, the minor components that facilitate or hinder grain growth and boundary formation may be be termed as additives. It may or may not be in solid solution with the parent phase/compound.
Dopants on the other hand, improve grain conductivity and they are essentially in solid solution with the parent phase/compound.
Hope this helps.
If my memory is not wrong the term dopant was used first in semiconductors where an n or p semiconductor can be obtained depending on the valence of the dopant atom that is added in a very small proportion. In that case dopant refer to a very small amount of a different species that changes the properties of a material dramatically.
A solid solution is whatever homogeneous mixture of elements, by homogeneous different things can be interpreted, it may be a crystalline solid containing different atomic species in the same crystallographic site or an amorphous material that remains homogeneous at some length scale relevant to the properties.
If you mix water and alcohol, they are 100% miscible so you can make a solution 10% water 90% alcohol or 10% alcolhol 90% water. Which is the solvent and the solute is a matter of definition. Solvent is always the majoritary part and solute the minoritary one. In the solid state the same is valid, so a dopant is always a solute.
In the end, it depends on the origin of the name, whether it is originated in the observation of a change of properties or just on the description of a certain state of matter.
Dopant is also used regarding substance abuse, where a small amount of a drug may have an importante physiological efect, in a very similar meaning of dopant in semiconductors...
Looking for those terms in an encyclopedia may do well in this case, without runing the risk of going away from scientific knowledge, since the use of the terms depends on the situation. For example wikipedia is good in describing Dopant and Solid Solution but the relation among those terms is missing...
You Know, I think all the definitions you've mentioned are right but I am looking for an standard term that specifies the amount ranges by specific names...I mean for example IUPAC determines the pores of a porous substance with particular names like nanopores,mesopores or macropores that each one can be used for their own specific size ranges not even 1 or 2 nanometers bigger or smaller....I wanted to know for example if the solute is not very small in amount should we change the name dopant (according to a special standard) because of the high amount although it is dissolved and is continuing the same application ?
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