Moore graph - Revision history

en>Stdazi: Added clarification about n and m

2014-11-28T09:02:04Z

Added clarification about n and m

← Older revision		Revision as of 11:02, 28 November 2014
Line 1:		Line 1:
	~~A '''Schottky defect'''~~ is ~~a type of [[Crystallographic defects#Point defects\|point defect]] in a [[crystal lattice]] named after [[Walter H~~. ~~Schottky]]. In non-ionic crystals it means~~		They call me Emilia. North Dakota is exactly where me and my husband live. For many years he's been operating as a receptionist. The factor she adores most is body building and now she is attempting to earn money with it.<br><br>Feel free to surf to my website; [http://reinodoprazer.com.br/index.php?do=/blog/326/tips-about-how-to-overcome-candidiasis-easily/ std testing at home]
	~~a lattice [[vacancy defect]].~~

	~~In ionic crystals, the defect forms when oppositely charged [[ion]]~~s leave their lattice sites, creating [[Vacancy defect\|vacancies]]. These vacancies are formed in [[Stoichiometry\|stoichiometric]] units, to maintain an overall neutral charge in the ionic solid. The vacancies are then free to move about as ~~their own entities. Normally these defects will lead to~~ a ~~decrease in the [[density]] of the crystal~~. The ~~following are the chemical equations in [[Kröger-Vink Notation]] for the formation of Schottky defects in TiO<sub>2</sub>~~ and ~~BaTiO<sub>3</sub>~~.

	Ø <~~math> \Leftrightarrow V_{Ti}'''' + 2V_O^{\bullet \bullet}</math~~>

	Ø <~~math~~> ~~\Leftrightarrow V_{Ba}'' + V_{Ti}'''' + 3V_O^{\bullet \bullet}</math>~~

	~~This can be illustrated schematically with a two-dimensional diagram of a~~ [~~[sodium chloride]] crystal lattice~~:

	~~[[Image:Nacllattice~~.~~svg\|thumb\|left\|The defect-free NaCl structure]]~~
	~~[[Image:Naclschottkydefect~~.~~svg\|thumb\|left\|Schottky defects within the NaCl structure]]~~

	<br ~~style~~=~~"clear:both;"~~/>

	~~==Definition==~~
	~~If in an ionic crystal of type A<sup>+<~~/~~sup>B<sup>~~-~~</sup> an equal number of cations and anions are missing from their lattice sites so that electrical neutrality as well as stoichiometry is maintained this is called a Schottky Defect.~~

	~~It is a vacancy defect (due to missing ions) and also a stoichiometric defect, as the ratio of the number of cations and anions remains the same.~~

	It occurs only when there is small difference in size between cations and anions. This is produced as the result of the thermal incorporation of unoccupied lattice sites from the exterior of the crystal. The lattice undergoes thermal vibration and thermal expansion when the temperature is raised above 0K. When it happens the pair of vacancies are incorporated in the crystal.

	~~==Examples==~~
	This type of defect is shown in highly ionic compounds, highly coordinated compounds, and where there is only a small difference in sizes of cations and anions of which the compound lattice is composed.

	* [[Sodium chloride\|NaCl]]
	* [[Potassium chloride\|KCl]]
	* [[Potassium bromide\|KBr]]
	* [[Caesium chloride\|CsCl]]
	* [[Silver chloride\|AgCl]]

	~~==Effect on Density==~~
	~~The total number of ions in a crystal with this defect is less than the theoretical value of ions, thus, the density of the solid crystal is less than normal.~~

	~~==See also==~~
	*[[Frenkel defect]]
	*[[Wigner effect]]
	*[[Crystallographic defects]]

	~~==References==~~
	~~{{reflist}}~~
	~~Kittel, Charles, Introduction to Solid State Physics~~ - ~~8th ed. Wiley, 2005. ISBN 0~~-~~471~~-~~41526~~-X.

	~~==External links==~~

	~~{{condensedmatter~~-~~stub}}~~
	~~[[Category:Crystallographic defects]~~]

en>ChrisGualtieri: General Fixes using AWB

2013-10-23T02:45:41Z

General Fixes using AWB

← Older revision		Revision as of 04:45, 23 October 2013
Line 1:		Line 1:
	~~Alyson Meagher~~ is the ~~title her mothers and fathers gave her but she doesn't like~~ when ~~individuals use her complete name~~. ~~Some time ago~~ [~~http://netwk~~.~~hannam~~.ac.kr/xe/~~data_2~~/~~85669 real psychic~~] ~~he chose to live in North Carolina and he doesn't strategy~~ free ~~psychic reading (~~[~~http~~://~~appin~~.~~co.kr/board_Zqtv22/688025 sneak~~ a ~~peek here]~~) ~~on altering it~~. It~~'s not a typical factor but what she likes performing~~ is ~~to perform domino but she doesn't have~~ the ~~time recently~~. ~~Office supervising~~ is ~~exactly~~ where ~~her main income arrives from but she's already utilized for another 1~~.~~<br><br>my web page: best psychic (~~[~~http://koreanyelp~~.~~com/index~~.~~php?document_srl~~=~~1798&mid~~=~~SchoolNews koreanyelp.com~~])		A '''Schottky defect''' is a type of [[Crystallographic defects#Point defects\|point defect]] in a [[crystal lattice]] named after [[Walter H. Schottky]]. In non-ionic crystals it means
			a lattice [[vacancy defect]].

			In ionic crystals, the defect forms when oppositely charged [[ion]]s leave their lattice sites, creating [[Vacancy defect\|vacancies]]. These vacancies are formed in [[Stoichiometry\|stoichiometric]] units, to maintain an overall neutral charge in the ionic solid. The vacancies are then free to move about as their own entities. Normally these defects will lead to a decrease in the [[density]] of the crystal. The following are the chemical equations in [[Kröger-Vink Notation]] for the formation of Schottky defects in TiO<sub>2</sub> and BaTiO<sub>3</sub>.

			Ø <math> \Leftrightarrow V_{Ti}'''' + 2V_O^{\bullet \bullet}</math>

			Ø <math> \Leftrightarrow V_{Ba}'' + V_{Ti}'''' + 3V_O^{\bullet \bullet}</math>

			This can be illustrated schematically with a two-dimensional diagram of a [[sodium chloride]] crystal lattice:

			[[Image:Nacllattice.svg\|thumb\|left\|The defect-free NaCl structure]]
			[[Image:Naclschottkydefect.svg\|thumb\|left\|Schottky defects within the NaCl structure]]

			<br style="clear:both;"/>

			==Definition==
			If in an ionic crystal of type A<sup>+</sup>B<sup>-</sup> an equal number of cations and anions are missing from their lattice sites so that electrical neutrality as well as stoichiometry is maintained this is called a Schottky Defect.

			It is a vacancy defect (due to missing ions) and also a stoichiometric defect, as the ratio of the number of cations and anions remains the same.

			It occurs only when there is small difference in size between cations and anions. This is produced as the result of the thermal incorporation of unoccupied lattice sites from the exterior of the crystal. The lattice undergoes thermal vibration and thermal expansion when the temperature is raised above 0K. When it happens the pair of vacancies are incorporated in the crystal.

			==Examples==
			This type of defect is shown in highly ionic compounds, highly coordinated compounds, and where there is only a small difference in sizes of cations and anions of which the compound lattice is composed.

			* [[Sodium chloride\|NaCl]]
			* [[Potassium chloride\|KCl]]
			* [[Potassium bromide\|KBr]]
			* [[Caesium chloride\|CsCl]]
			* [[Silver chloride\|AgCl]]

			==Effect on Density==
			The total number of ions in a crystal with this defect is less than the theoretical value of ions, thus, the density of the solid crystal is less than normal.

			==See also==
			*[[Frenkel defect]]
			*[[Wigner effect]]
			*[[Crystallographic defects]]

			==References==
			{{reflist}}
			Kittel, Charles, Introduction to Solid State Physics - 8th ed. Wiley, 2005. ISBN 0-471-41526-X.

			==External links==

			{{condensedmatter-stub}}
			[[Category:Crystallographic defects]]

en>Rezabot: r2.7.1) (Robot: Adding fa:گراف مور

2012-01-11T11:03:11Z

r2.7.1) (Robot: Adding fa:گراف مور

New page

Alyson Meagher is the title her mothers and fathers gave her but she doesn't like when individuals use her complete name. Some time ago [http://netwk.hannam.ac.kr/xe/data_2/85669 real psychic] he chose to live in North Carolina and he doesn't strategy free psychic reading ([http://appin.co.kr/board_Zqtv22/688025 sneak a peek here]) on altering it. It's not a typical factor but what she likes performing is to perform domino but she doesn't have the time recently. Office supervising is exactly where her main income arrives from but she's already utilized for another 1.<br><br>my web page: best psychic ([http://koreanyelp.com/index.php?document_srl=1798&mid=SchoolNews koreanyelp.com])