{"id":5632,"date":"2017-03-23T17:22:57","date_gmt":"2017-03-23T10:22:57","guid":{"rendered":"http:\/\/ttud.com.vn\/?p=5632"},"modified":"2017-10-03T13:10:39","modified_gmt":"2017-10-03T06:10:39","slug":"kim-loai-sieu-dac-biet-co-the-ghi-nho-dac-tinh-o-dang-long-cua-chinh-no","status":"publish","type":"post","link":"https:\/\/casta.ttud.com.vn\/index.php\/kim-loai-sieu-dac-biet-co-the-ghi-nho-dac-tinh-o-dang-long-cua-chinh-no\/","title":{"rendered":"Kim lo\u1ea1i si\u00eau \u0111\u1eb7c bi\u1ec7t c\u00f3 th\u1ec3 ghi nh\u1edb \u0111\u1eb7c t\u00ednh \u1edf d\u1ea1ng l\u1ecfng c\u1ee7a ch\u00ednh n\u00f3"},"content":{"rendered":"

C\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u \u0111\u00e3 kh\u1ea3o s\u00e1t m\u1eabu kim lo\u1ea1i bismuth v\u00e0 t\u00ecm th\u1ea5y m\u1ed9t \u0111\u1eb7c \u0111i\u1ec3m ho\u00e0n to\u00e0n g\u00e2y b\u1ea5t ng\u1edd cho t\u1ea5t c\u1ea3 m\u1ecdi ng\u01b0\u1eddi \u0111\u00f3 l\u00e0 trong m\u1ed9t \u0111i\u1ec1u ki\u1ec7n nh\u1ea5t \u0111\u1ecbnh, kim lo\u1ea1i r\u1eafn n\u00e0y c\u00f3 th\u1ec3 t\u1ed3n t\u1ea1i \u1edf d\u1ea1ng c\u1ea5u tr\u00fac m\u00e0 ch\u1ec9 t\u1ed3n t\u1ea1i d\u01b0\u1edbi tr\u1ea1ng th\u00e1i l\u1ecfng.<\/strong><\/p>\n

\"\"<\/p>\n

Th\u1ef1c t\u1ebf l\u00e0 ngo\u00e0i vi\u1ec7c t\u00ecm th\u1ea5y m\u1ed9t t\u00ednh ch\u1ea5t m\u1edbi c\u1ee7a kim lo\u1ea1i th\u00ec \u0111i\u1ec1u n\u00e0y c\u0169ng c\u00f3 ngh\u0129a l\u00e0 bismuth r\u1eafn c\u00f3 th\u1ec3 chuy\u1ec3n t\u1eeb b\u1ecb \u0111\u1ea9y b\u1edfi m\u1ed9t t\u1eeb tr\u01b0\u1eddng (ngh\u1ecbch t\u1eeb) tr\u1edf th\u00e0nh b\u1ecb h\u00fat v\u00e0o m\u1ed9t t\u1eeb tr\u01b0\u1eddng (s\u1eaft t\u1eeb), v\u00e0 \u0111i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn m\u1ed9t ph\u01b0\u01a1ng c\u00e1ch ho\u00e0n to\u00e0n m\u1edbi \u0111\u1ec3 t\u1ea1o ra v\u1eadt li\u1ec7u m\u1edbi c\u00f3 t\u00ednh ch\u1ea5t \u0111\u1ed9c \u0111\u00e1o.<\/p>\n

Trong c\u00e1c d\u1ea1ng t\u1ed3n t\u1ea1i c\u1ee7a v\u1eadt ch\u1ea5t nh\u01b0 ch\u1ea5t l\u1ecfng, kh\u00ed v\u00e0 r\u1eafn, t\u1ea5t c\u1ea3 \u0111\u1ec1u \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1edfi s\u1ef1 s\u1eafp x\u1ebfp c\u1ea5u tr\u00fac c\u1ee7a c\u00e1c ph\u00e2n t\u1eed v\u00e0 ph\u1ee5 thu\u1ed9c v\u00e0o \u0111i\u1ec1u ki\u1ec7n b\u00ean ngo\u00e0i. V\u00ed d\u1ee5 qu\u00e1 tr\u00ecnh \u0111\u00f3ng b\u0103ng, tan ch\u1ea3y v\u00e0 b\u1ed1c h\u01a1i c\u1ee7a n\u01b0\u1edbc.<\/p>\n

Nh\u01b0ng bismuth l\u00e0 m\u1ed9t trong nh\u1eefng nguy\u00ean t\u1ed1 kh\u00f4ng \u0111\u01a1n gi\u1ea3n. Ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u00ecm th\u1ea5y \u1edf d\u1ea1ng r\u1eafn, nh\u01b0ng d\u01b0\u1edbi s\u1ef1 gia t\u0103ng \u0111i\u1ec1u ki\u1ec7n \u00e1p su\u1ea5t v\u00e0 nhi\u1ec7t \u0111\u1ed9, c\u00f3 th\u1ec3 tr\u1ea3i qua m\u1ed9t giai \u0111o\u1ea1n chuy\u1ec3n ti\u1ebfp c\u00f3 qu\u1ea3ng r\u1ed9ng v\u00e0 k\u00e9o d\u00e0i h\u01a1n b\u00ecnh th\u01b0\u1eddng. c\u00e1c nh\u00e0 khoa h\u1ecdc \u0111\u00e3 quan s\u00e1t th\u1ea5y t\u00e1m lo\u1ea1i pha r\u1eafn kh\u00e1c nhau c\u1ee7a kim lo\u1ea1i n\u00e0y cho \u0111\u1ebfn nay.<\/p>\n

M\u1ed9t trong nh\u1eefng \u0111\u1eb7c t\u00ednh th\u00fa v\u1ecb nh\u1ea5t c\u1ee7a bismuth l\u00e0 khi n\u00f3 t\u1ed3n t\u1ea1i d\u01b0\u1edbi d\u1ea1ng r\u1eafn s\u1ebd b\u1ecb \u0111\u1ea9y l\u00f9i, nh\u1edd m\u1ed9t hi\u1ec7n t\u01b0\u1ee3ng g\u1ecdi l\u00e0 ngh\u1ecbch t\u1eeb, nh\u01b0ng d\u01b0\u1edbi \u00e1p su\u1ea5t cao v\u00e0 nhi\u1ec7t \u0111\u1ed9 cao – th\u01b0\u1eddng tr\u00f9ng v\u1edbi \u0111i\u1ec1u ki\u1ec7n t\u1ed3n t\u1ea1i d\u01b0\u1edbi tr\u1ea1ng th\u00e1i l\u1ecfng – kim lo\u1ea1i c\u00f3 th\u1ec3 tr\u1edf th\u00e0nh s\u1eaft t\u1eeb.<\/p>\n

B\u1edfi v\u00ec t\u00ednh ch\u1ea5t k\u1ef3 l\u1ea1 n\u00e0y, c\u00e1c nh\u00e0 khoa h\u1ecdc \u0111\u00e3 s\u1eed d\u1ee5ng bismuth \u0111\u1ec3 th\u1ef1c hi\u1ec7n r\u1ea5t nhi\u1ec1u th\u00ed nghi\u1ec7m quan tr\u1ecdng v\u1ec1 \u1ea3nh h\u01b0\u1edfng c\u1ee7a t\u1eeb tr\u01b0\u1eddng v\u1ec1 \u0111\u1ed9 d\u1eabn \u0111i\u1ec7n (th\u01b0\u1eddng b\u1edfi v\u00ec bismuth l\u00e0 m\u1ed9t ch\u1ea5t d\u1eabn v\u00f4 c\u00f9ng y\u1ebfu). V\u00e0 gi\u1edd \u0111\u00e2y ch\u00fang ta l\u1ea1i t\u00ecm th\u1ea5y m\u1ed9t t\u00ednh ch\u1ea5t k\u1ef3 l\u1ea1 kh\u00e1c v\u1ec1 kim lo\u1ea1i n\u00e0y – \u0111\u00f3 l\u00e0 d\u01b0\u1eddng nh\u01b0 n\u00f3 c\u00f3 kh\u1ea3 n\u0103ng gi\u1eef l\u1ea1i t\u00ednh ch\u1ea5t “ghi nh\u1edb c\u1ea5u tr\u00fac” c\u1ee7a pha l\u1ecfng, ngay c\u1ea3 khi n\u00f3 \u0111ang t\u1ed3n t\u1ea1i d\u01b0\u1edbi d\u1ea1ng ch\u1ea5t r\u1eafn.<\/p>\n

T\u00ednh ch\u1ea5t “ghi nh\u1edb” v\u00e0 ph\u1ee5c h\u1ed3i l\u1ea1i c\u1ea5u tr\u00fac ban \u0111\u1ea7u \u1edf kim lo\u1ea1i kh\u00f4ng ph\u1ea3i l\u00e0 m\u1edbi – ng\u01b0\u1eddi ta \u0111\u00e3 ch\u1ebf t\u1ea1o \u0111\u01b0\u1ee3c c\u00e1c h\u1ee3p kim c\u00f3 kh\u1ea3 n\u0103ng ph\u1ee5c h\u1ed3i l\u1ea1i h\u00ecnh d\u1ea1ng v\u00e0 c\u1ea5u tr\u00fac ban \u0111\u1ea7u khi \u0111\u01b0\u1ee3c t\u00e1c d\u1ee5ng b\u1eb1ng m\u1ed9t nhi\u1ec7t \u0111\u1ed9 v\u00e0 \u00e1p su\u1ea5t nh\u1ea5t \u0111\u1ecbnh. C\u00e1c h\u1ee3p kim n\u00e0y c\u00f3 m\u1ed9t s\u1ef1 s\u1eafp x\u1ebfp ri\u00eang bi\u1ec7t khi\u1ebfn ch\u00fang lu\u00f4n lu\u00f4n ph\u1ee5c h\u1ed3i l\u1ea1i khi \u0111un n\u00f3ng ho\u1eb7c l\u00e0m l\u1ea1nh \u0111\u1ebfn m\u1ed9t nhi\u1ec7t \u0111\u1ed9 nh\u1ea5t \u0111\u1ecbnh. Nh\u01b0ng s\u1ef1 ph\u1ee5c h\u1ed3i n\u00e0y lu\u00f4n di\u1ec5n ra \u1edf tr\u1ea1ng th\u00e1i r\u1eafn – c\u00e1c kim lo\u1ea1i kh\u00f4ng \u0111\u01b0\u1ee3c nh\u1ea3y gi\u1eefa c\u00e1c pha kh\u00e1c nhau.<\/p>\n

Trong nghi\u00ean c\u1ee9u n\u00e0y, c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u t\u1eeb Vi\u1ec7n Khoa h\u1ecdc Carnegie th\u1ef1c hi\u1ec7n tr\u00ean bismuth v\u1edbi tr\u1ea1ng th\u00e1i l\u1ecfng \u1edf \u00e1p su\u1ea5t l\u1edbn \u0111\u00e1ng kinh ng\u1ea1c (14.000 \u0111\u1ebfn 24.000 l\u1ea7n so v\u1edbi \u00e1p su\u1ea5t kh\u00ed quy\u1ec3n b\u00ecnh th\u01b0\u1eddng), v\u00e0 nhi\u1ec7t \u0111\u1ed9 v\u00e0o kho\u1ea3ng 1.250 Kelvin (977 \u0111\u1ed9 C, ho\u1eb7c 1.800 \u0111\u1ed9 F). Khi l\u00e0m m\u00e1t t\u1eeb t\u1eeb bismuth tr\u1edf l\u1ea1i tr\u1ea1ng th\u00e1i r\u1eafn, h\u1ecd th\u1ea5y r\u1eb1ng bismuth r\u1eafn “ghi nh\u1edb” m\u1ed9t s\u1ed1 c\u1ea5u tr\u00fac d\u01b0\u1edbi d\u1ea1ng ch\u1ea5t l\u1ecfng c\u1ee7a n\u00f3. \u0110i\u1ec1u \u0111\u00f3 kh\u00f4ng c\u00f3 ngh\u0129a l\u00e0 bismuth chuy\u1ec3n \u0111\u1ed5i tr\u1edf l\u1ea1i th\u00e0nh h\u00ecnh d\u1ea1ng l\u1ecfng \u0111\u00e3 c\u00f3 tr\u01b0\u1edbc, m\u00e0 n\u00f3 \u0111\u00e3 ghi nh\u1edb t\u00ednh ch\u1ea5t s\u1eaft t\u1eeb tr\u1ea1ng th\u00e1i l\u1ecfng \u0111\u00f3 l\u00e0 b\u1ecb thu h\u00fat b\u1edfi m\u1ed9t t\u1eeb tr\u01b0\u1eddng, ch\u1ee9 kh\u00f4ng ph\u1ea3i l\u00e0 b\u1ecb \u0111\u1ea9y nh\u01b0 b\u00ecnh th\u01b0\u1eddng.<\/p>\n

“Ch\u1ea5t l\u1ecfng d\u01b0\u1edbi \u00e1p su\u1ea5t cao v\u00e0 nhi\u1ec7t \u0111\u1ed9 cao khi\u1ebfn c\u1ea5u tr\u00fac ph\u00e2n t\u1eed b\u1ecb h\u1ed7n lo\u1ea1n, \u0111i\u1ec1u n\u00e0y \u0111\u01b0a ch\u1ea5t l\u1ecfng v\u1ec1 d\u1ea1ng t\u1ed3n t\u1ea1i s\u00e2u v\u00e0 khi\u1ebfn cho t\u00ednh ch\u1ea5t d\u01b0\u1edbi pha l\u1ecfng c\u1ee7a bismuth \u0111\u01b0\u1ee3c “ghi nh\u1edb” sau khi l\u00e0m l\u1ea1nh cho \u0111\u1ebfn khi r\u1eafn l\u1ea1i” – Guoyin Shen, m\u1ed9t trong nh\u1eefng nh\u00e0 nghi\u00ean c\u1ee9u gi\u1ea3i th\u00edch.<\/p>\n

“\u0110\u00e2y l\u00e0 l\u1ea7n \u0111\u1ea7u ti\u00ean m\u1ed9t hi\u1ec7u \u1ee9ng nh\u01b0 v\u1eady \u0111\u01b0\u1ee3c quan s\u00e1t th\u1ea5y trong m\u1ed9t nguy\u00ean t\u1ed1 kim lo\u1ea1i”.<\/p>\n

Cho \u0111\u1ebfn b\u00e2y gi\u1edd nh\u00f3m nghi\u00ean c\u1ee9u v\u1eabn kh\u00f4ng ho\u00e0n to\u00e0n ch\u1eafc ch\u1eafn s\u1ef1 ghi nh\u1edb c\u1ea5u tr\u00fac n\u00e0y \u0111\u01b0\u1ee3c l\u01b0u tr\u1eef trong bismuth nh\u01b0 th\u1ebf n\u00e0o, ho\u1eb7c l\u00e0m th\u1ebf n\u00e0o bismuth r\u1eafn c\u00f3 kh\u1ea3 n\u0103ng ho\u1ea1t \u0111\u1ed9ng nh\u01b0 m\u1ed9t ch\u1ea5t s\u1eaft t\u1eeb, thay v\u00ec b\u1ecb \u0111\u1ea9y l\u00f9i nam ch\u00e2m nh\u01b0 b\u00ecnh th\u01b0\u1eddng.<\/p>\n

“Ngu\u1ed3n g\u1ed1c v\u1eadt l\u00fd c\u1ee7a hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y th\u1ef1c s\u1ef1 \u0111\u00e1ng ng\u1ea1c nhi\u00ean v\u00e0 c\u1ea7n th\u00eam nh\u1eefng nghi\u00ean c\u1ee9u b\u1ed5 sung”, nh\u00f3m nghi\u00ean c\u1ee9u \u0111\u0103ng tr\u00ean t\u1ea1p ch\u00ed PNAS.<\/p>\n

Nh\u01b0ng \u0111\u1ed3ng th\u1eddi nh\u00f3m c\u0169ng cho r\u1eb1ng t\u00ednh ch\u1ea5t m\u1edbi l\u1ea1 n\u00e0y c\u0169ng c\u00f3 th\u1ec3 g\u00e2y ra m\u1ed9t s\u1ef1 thay \u0111\u1ed5i t\u01b0\u01a1ng t\u1ef1 trong c\u00e1c nguy\u00ean t\u1ed1 kh\u00e1c, ch\u1eb3ng h\u1ea1n nh\u01b0 cerium, antimon, v\u00e0 plutonium. V\u00e0 n\u1ebfu \u0111i\u1ec1u n\u00e0y \u0111\u01b0\u1ee3c nghi\u00ean c\u1ee9u s\u00e2u h\u01a1n th\u00ec c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn m\u1ed9t ph\u01b0\u01a1ng c\u00e1ch ho\u00e0n to\u00e0n m\u1edbi \u0111\u1ec3 t\u1ea1o ra nh\u1eefng y\u1ebfu t\u1ed1 c\u00f3 t\u00ednh ch\u1ea5t \u0111\u1eb7c bi\u1ec7t ch\u01b0a \u0111\u01b0\u1ee3c khai th\u00e1c.<\/p>\n

Ngu\u1ed3n khampha<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

C\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u \u0111\u00e3 kh\u1ea3o s\u00e1t m\u1eabu kim lo\u1ea1i bismuth v\u00e0 t\u00ecm th\u1ea5y m\u1ed9t \u0111\u1eb7c \u0111i\u1ec3m ho\u00e0n to\u00e0n g\u00e2y b\u1ea5t ng\u1edd cho t\u1ea5t c\u1ea3 m\u1ecdi ng\u01b0\u1eddi \u0111\u00f3 l\u00e0 trong m\u1ed9t \u0111i\u1ec1u ki\u1ec7n nh\u1ea5t \u0111\u1ecbnh, kim lo\u1ea1i r\u1eafn n\u00e0y c\u00f3 th\u1ec3 t\u1ed3n t\u1ea1i \u1edf d\u1ea1ng c\u1ea5u tr\u00fac m\u00e0 ch\u1ec9 t\u1ed3n t\u1ea1i d\u01b0\u1edbi tr\u1ea1ng th\u00e1i l\u1ecfng. […]<\/p>\n","protected":false},"author":17,"featured_media":6740,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[],"class_list":["post-5632","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tin-tuc"],"_links":{"self":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5632","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/users\/17"}],"replies":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/comments?post=5632"}],"version-history":[{"count":2,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5632\/revisions"}],"predecessor-version":[{"id":6741,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5632\/revisions\/6741"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/media\/6740"}],"wp:attachment":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/media?parent=5632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/categories?post=5632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/tags?post=5632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}