{"id":437,"date":"2021-12-31T15:19:32","date_gmt":"2021-12-31T21:19:32","guid":{"rendered":"http:\/\/www.nano-blog.com\/?p=437"},"modified":"2022-09-02T12:48:36","modified_gmt":"2022-09-02T17:48:36","slug":"ultra-pure-material","status":"publish","type":"post","link":"http:\/\/www.nano-blog.com\/?p=437","title":{"rendered":"Ultra-pure material"},"content":{"rendered":"\n<p>We already reported on the development of two-dimensional nano-sheet transistors and other two-dimensional materials.&nbsp; One of the challenges that has been previously mentioned is the fact that we do not know the material properties of \u201cpure\u201d materials.&nbsp; Current technology provides the ability to achieve purities within a range of parts per million.&nbsp; In the percentage parlance that is 99.9999% pure material.&nbsp; It is expensive and needed. &nbsp;Doping silicon wafers with specific impurities can change the bandgap (conductivity increase or decrease) of the resultant material to enable the desired structure flow of electrons. &nbsp;While the percentage of material purity Sound excellent, there is another way of looking at the analysis.&nbsp;<\/p>\n\n\n\n<p>Reference 1 refers to an analysis by Flavio Matsumoto on the number of osmium atoms in a cubic centimeter.&nbsp; He performs the calculation tow different ways and the answers are close.&nbsp; Both result in 7 x 10<sup>22<\/sup> atoms, with a fractional difference.&nbsp; Depending on the specific element, the number will vary.&nbsp; If the material (osmium in this example) is 99.9999999% pure, there will be 7 x 10<sup>13<\/sup> non osmium atoms in the cubic centimeter.&nbsp; If one then reduces the size in question to one micron cubed, there will be 7 non osmium atoms present.&nbsp; What happens when materials get near being without impurities?&nbsp; &nbsp;<\/p>\n\n\n\n<p>Princeton researchers [Ref. 2] have created a sample of gallium arsenide with impurities of one atom in ten billion.&nbsp; The size of the material was 5 or 6 millimeters cubed.&nbsp; To test the material, the cooled it to temperatures equivalent to space and inserted the material in a strong magnetic field.&nbsp; They were interested in observing the changes in the electron flow.&nbsp; They were surprised in that they found that many of the advanced physics phenomena were able to be observed at weaker magnetic fields.&nbsp; From the data, it appears that the resultant effects could be observed at two orders of magnitude less than fields required to observe the phenomena in less pure materials.&nbsp;<\/p>\n\n\n\n<p>Our current technology permits us to make changes in the electrical conductivity of materials by adding a small amount of specific impurities (doping).&nbsp; It is also known that adding impurities changes the structural lattice to advance or retard the ability of electrons to move within the lattice.&nbsp; Since the lattice structure is changed, the question that remains is what happens to various other properties of the material.&nbsp; In order to address that question, various quantities of absolutely pure material need to be created.&nbsp; The raises the challenge on developing the processes for removing the impurities for the current methods of obtaining the current \u201chigh purity\u201d materials.<\/p>\n\n\n\n<p>This is a non-trivial problem.&nbsp; Graphene has been manufactured for 20 plus years.&nbsp; There is still a challenge to obtain a large area of graphene without structural defects.&nbsp; Impurities can create those structural defects.&nbsp; The work being done on two-dimensions transistors, which can accommodate some defects, has not developed a process that can be employed to create the billions of transistors required for one microprocessor chip.<\/p>\n\n\n\n<p>The new year, 2022, should provide some interesting developments that further our understanding of pure materials.<\/p>\n\n\n\n<p>References:<\/p>\n\n\n\n<ol class=\"wp-block-list\" type=\"1\"><li><a href=\"https:\/\/www.quora.com\/How-many-atoms-of-osmium-are-there-in-one-cubic-centimeter-I-honestly-cant-find-any-internet-help-whatsoever\">https:\/\/www.quora.com\/How-many-atoms-of-osmium-are-there-in-one-cubic-centimeter-I-honestly-cant-find-any-internet-help-whatsoever<\/a><\/li><li><a href=\"https:\/\/phys.org\/news\/2021-11-ultra-pure-semiconductor-frontier-electrons.html\">https:\/\/phys.org\/news\/2021-11-ultra-pure-semiconductor-frontier-electrons.html<\/a><\/li><\/ol>\n","protected":false},"excerpt":{"rendered":"<p>We already reported on the development of two-dimensional nano-sheet transistors and other two-dimensional materials.&nbsp; One of the challenges that has been previously mentioned is the fact that we [..]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-437","post","type-post","status-publish","format-standard","hentry","category-science"],"_links":{"self":[{"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=\/wp\/v2\/posts\/437","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=437"}],"version-history":[{"count":1,"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=\/wp\/v2\/posts\/437\/revisions"}],"predecessor-version":[{"id":438,"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=\/wp\/v2\/posts\/437\/revisions\/438"}],"wp:attachment":[{"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=437"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=437"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.nano-blog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=437"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}