Alloying implies using a metal as the impurity that should be blended with the base material (also another metal or metal composition), but doping involves more general meaning and is used when one substance is mixed with other one.
What I figure out, doping refers to adding an element in very small quantities (ppm or ppb) in a material. Doppants normally are taken into solid solution. It is for altering the behaviour or some physical properties as commonly used in the manufacture of electronic materials. Alloying generally contain elements in higher quantities and the purpose can be to alter physical, mechanical or chemical properties. The alloy need not to be single phase. There may be more differences but this seems more obvious.
The main difference is quantity and the effect of the other metal mixed
when metals are mixed in large proportion and they have homogenous mixture they are called alloying, allowing metals give new property to the mixture.
When a metal in very low quantity is spread in some other metal to improve it's quality it is called dopping.
How to quantify the dopant/alloying element concentration? Whether quantity of a second phase/element differentiating between doping and alloying is the solid solubility limit of that phase/element to the host phase ?
In alloying the addition may not be a metal like P or B. I think the emphasis is one quantity, solubility and the way (process) it is added. Like P present as dopant in semiconductors very small quantities while it may be present in Cu in larger quantity as an alloying addition. Similar examples can be found in scientific literature.
It can be taken as alloying is done to combine the property of two materials say A & B
and
Doping is done to increase or decrese the property of material A by adding material B
Doping is normally a physical reaction and only take place on the surface of the metal.
Alloying is a chemical reaction between two or more metal ions to form an alloy compound. It usually alter the crystal structure as a whole.
Dear Mr. Subhsisa Nath Doping in Metallurgy means the addition of a second material in minute qty to a large qty of a first material. The addition may or may not result in a crystal structure change of the first material and the effect will be a change in the properties of the doped material superficial only. But alloying metal means the alloying element can be either in small or large %ages and there is a definite change in both lattice and micro structures. Hope this clarifies your doubt?
Dear all,
I may be stupid to some people, but I had asked the question in an intention. I have some work with the material zirconia. To stabilize the phase (either tetragonal or cubic), yttria is added in different fractions in zirconia. Yttria is actually added as a dopant. But some researchers also follow the term "Yttria-Zirconia alloy". So I wanted to clear my doubt with you people.
Your starting question is a good homework-type essay problem for an introductory materials science course. Most of the answers given here already should be helpful. One big mistake is from YMB Ismail ... the presence or not of chemical reactions has absolutely nothing to do with how the terms are to be defined in their every-day applications. In fact, when two components react chemically, a compound forms, and we have neither a doped material nor an alloy.
Based on your further clarification, you might now want to review the literature for the differences between those researchers who call their material a yttria doped zirconium versus those who call their material a yttria-zirconia alloy. What chemistry and structure do these authors say their materials have? What properties do they say their materials have? Do you find any differences in chemistry, structure, and/or properties are always present when they talk about doping versus alloying? Or is the terminology doped versus alloy used so ambiguously by researchers to describe yttria + zirconium materials that you cannot decide what they really mean? This type of problem would not be an uncommon one. The studies you are reading are probably being done by folks from a wide range of disciplines, and some of them may have no formal training in the terminology or have mistaken ideas about the terms doping versus alloying.
Dear Subhasiha
If you go through the phase diagram of (YSZ).
you are able to see that the cubic phase will be stable when the concentration of yttria is more than 7% "the phase transformation will not take place". Means it will be stable (cubic) phase at all temperature.
generally doping represent the less concentration (ppm) level.
But alloying represent solid solution.
There will be no chemical reaction between the alloying elements.
In some materials if concentration reach the solid solution limit .. then it will grow as a precipitate (compound) may be inter-metallic, ceramic in which metallic bond no more exist..
For example: like Fe3C cementite a inter-metallic starts forming when C concentration is higher than 2% (α+Fe3C) .
In doping, dopant is replacing the target lattice, without changing the crystal structure of the parent material. However, in alloying structure and properties of the final material may change significantly compare to parent materials.
We, the people working in the broad spectrum of Materials science are often confused with the terms "Solid Solution", "Doping", "Alloying", Compound Formation. To me, the first three terms are essentially the same and refer to mixture formation. Doping is addition of a secondary material while retaining the phase of the first such that macroscopically the presence and identity of the second phase is not revealed. The incoming atom may take a lattice position when it is called substitutional or take an interstitial position. It is simply the case of solution formation, when sugar is dissolved in water, which is why by analogy the doped materials are also called Solid Solution. By analogy, the material in small amount is called the solute and the major one is the solvent. Alloying by definition, is a solid solution where one of the two components is a metal. If the doping is more, that is if the amount of solute exceeds the solubility limit, then the solute tends to precipitate out either in the native form or as a reaction product. Presence of more than one identifiable phase is known as Composite. But how is it different from compound formation? Essentially, doping amount may be varied within a range but compounds always have fixed composition. To illustrate, when ~2% atoms are replaced in a compound, the environment around every atom is not changed although we may write the formula Ca(3-x)Srx(PO4)2, where x=0.06. But in a compound like Ca3(PO4)2, each calcium atom must have two PO4 units.
Please suggest me books about doping and substitution of metals
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