C\u00e1i danh t\u1eeb ch\u1ea5t d\u1eabn (\u0111i\u1ec7n) kh\u00f4ng xa l\u1ea1 g\u00ec \u0111\u1ed1i v\u1edbi ch\u00fang ta c\u1ea3. H\u1eb1ng ng\u00e0y, khi ch\u00fang ta b\u1eadt ra\u0111i\u00f4 hay tivi, ch\u1ea5t d\u1eabn li\u1ec1n hi\u1ec7n r\u00f5 ngay, chuy\u1ec3n bi\u1ebfn t\u00edn hi\u1ec7u \u0111i\u1ec7n th\u00e0nh \u00e2m nh\u1ea1c du d\u01b0\u01a1ng v\u00e0 h\u00ecnh \u1ea3nh t\u01b0\u01a1i \u0111\u1eb9p. S\u1edf d\u0129 ch\u1ea5t d\u1eabn c\u00f3 \u0111\u01b0\u1ee3c t\u00ednh n\u0103ng d\u1eabn \u0111i\u1ec7n r\u1ea5t t\u1ed1t l\u00e0 do k\u1ebft c\u1ea5u n\u1ed9i b\u1ed9 c\u1ee7a ch\u00fang quy\u1ebft \u0111\u1ecbnh. Song, b\u1ea5t k\u1ec3 l\u00e0 ch\u1ea5t d\u1eabn n\u00e0o, tr\u00ean \u0111\u01b0\u1eddng \u0111i c\u1ee7a d\u00f2ng \u0111i\u1ec7n bao gi\u1edd c\u0169ng sinh ra l\u1ef1c c\u1ea3n \u0111\u1ed1i v\u1edbi d\u00f2ng \u0111i\u1ec7n. Khi m\u1ed9t d\u00f2ng \u0111i\u1ec7n r\u1ea5t m\u1ea1nh di qua d\u00e2y d\u1eabn, d\u00e2y s\u1ebd n\u00f3ng l\u00ean, \u0111\u00f3 ch\u00ednh l\u00e0 lo\u1ea1i l\u1ef1c c\u1ea3n, l\u00e0 \u0111i\u1ec7n tr\u1edf trong d\u00e2y g\u00e2y ra. Ch\u00ednh v\u00ec c\u00f3 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a \u0111i\u1ec7n tr\u1edf, n\u0103ng l\u01b0\u1ee3ng c\u1ee7a d\u00f2ng \u0111i\u1ec7n kh\u00f4ng th\u1ec3 kh\u00f4ng chia ra m\u1ed9t ph\u1ea7n ti\u00eau hao tr\u00ean \u0111i\u1ec7n tr\u1edf, qua \u0111\u00f3 l\u00e0m cho \u0111i\u1ec7n n\u0103ng h\u1eefu d\u1ee5ng b\u1ecb l\u00e3ng ph\u00ed v\u00f4 \u00edch.<\/p>\n\n\n\n
D\u00f2ng \u0111i\u1ec7n ch\u1ea1y trong ch\u1ea5t d\u1eabn \u0111i\u1ec7n nh\u01b0 th\u1ebf n\u00e0o? C\u00f3 t\u1ed3n t\u1ea1i ch\u1ea5t d\u1eabn \u0111i\u1ec7n ho\u00e0n to\u00e0n kh\u00f4ng c\u00f3 \u0111i\u1ec7n tr\u1edf hay kh\u00f4ng? \u0110\u00f3 l\u00e0 hai v\u1ea5n \u0111\u1ec1 m\u00e0 con ng\u01b0\u1eddi r\u1ea5t quan t\u00e2m.<\/p>\n\n\n\n
Th\u00ec ra, s\u1ef1 chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a d\u00f2ng \u0111i\u1ec7n l\u00e0 do m\u1ed9t lo\u1ea1i l\u1ef1c \u0111\u1eb7c bi\u1ec7t – l\u1ef1c \u0111i\u1ec7n tr\u01b0\u1eddng g\u00e2y ra. Khi d\u00f2ng \u0111i\u1ec7n g\u1eb7p ph\u1ea3i \u0111i\u1ec7n tr\u1edf, t\u1ed1c \u0111\u1ed9 chuy\u1ec3n \u0111\u1ed9ng b\u1ecb ch\u1eadm l\u1ea1i, l\u1ef1c \u0111i\u1ec7n tr\u01b0\u1eddng li\u1ec1n “ra tay gi\u00fap \u0111\u1ee1” \u0111\u1ec3 d\u00f2ng \u0111i\u1ec7n v\u01b0\u1ee3t qua l\u1ef1c c\u1ea3n m\u00e0 ch\u1ea1y kh\u00f4ng ng\u1eebng trong d\u00e2y d\u1eabn. Ngu\u1ed3n sinh ra ngo\u1ea1i l\u1ef1c \u0111i\u1ec7n tr\u01b0\u1eddng n\u00e0y l\u00e0 ngu\u1ed3n \u0111i\u1ec7n. N\u1ebfu trong d\u00e2y d\u1eabn kh\u00f4ng c\u00f3 \u0111i\u1ec7n tr\u1edf th\u00ec s\u1ef1 chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a d\u00f2ng \u0111i\u1ec7n kh\u00f4ng c\u00f2n c\u1ea7n \u0111\u1ebfn s\u1ef1 th\u00fac \u0111\u1ea9y c\u1ee7a l\u1ef1c \u0111i\u1ec7n tr\u01b0\u1eddng m\u00e0 c\u00f3 th\u1ec3 ch\u1ea1y m\u00e3i \u0111\u01b0\u1ee3c. Ch\u1ea5t d\u1eabn \u0111i\u1ec7n nh\u01b0 v\u1eady g\u1ecdi l\u00e0 ch\u1ea5t d\u1eabn \u0111i\u1ec7n ho\u00e0n to\u00e0n. Trong ch\u1ea5t d\u1eabn ho\u00e0n to\u00e0n, l\u1ef1c \u0111i\u1ec7n tr\u01b0\u1eddng ch\u1eb3ng nh\u1eefng kh\u00f4ng c\u00f3 “\u0111\u1ea5t d\u1ee5ng v\u00f5”, m\u00e0 c\u00f2n ho\u00e0n to\u00e0n kh\u00f4ng c\u00f3 “ch\u1ed7 dung th\u00e2n”. V\u00ec trong ch\u1ea5t d\u1eabn ho\u00e0n to\u00e0n kh\u00f4ng c\u00f2n \u0111i\u1ec7n tr\u1edf n\u1eefa, \u0111i\u1ec7n t\u00edch m\u1ed9t khi ch\u1ecbu l\u1ef1c th\u00ec s\u1ebd c\u00e0ng ch\u1ea1y c\u00e0ng nhanh, r\u1ed1t cu\u1ed9c l\u00e0m cho d\u00f2ng \u0111i\u1ec7n trong ch\u1ea5t d\u1eabn tr\u1edf n\u00ean ng\u00e0y c\u00e0ng l\u1edbn, \u0111\u1ebfn n\u1ed7i kh\u00f4ng sai khi\u1ebfn \u0111\u01b0\u1ee3c. Trong hi\u1ec7n th\u1ef1c, lo\u1ea1i t\u00ecnh h\u00ecnh n\u00e0y kh\u00f4ng th\u1ec3 n\u00e0o xu\u1ea5t hi\u1ec7n ra. V\u00ec v\u1eady, trong ch\u1ea5t d\u1eabn ho\u00e0n to\u00e0n kh\u00f4ng th\u1ec3 t\u1ed3n t\u1ea1i l\u1ef1c \u0111i\u1ec7n tr\u01b0\u1eddng. C\u00e1c nh\u00e0 khoa h\u1ecdc \u0111\u00e3 ch\u1ee9ng minh r\u1eb1ng lo\u1ea1i l\u1ef1c \u0111i\u1ec7n tr\u01b0\u1eddng n\u00e0y c\u00f2n sinh ra t\u1eeb tr\u01b0\u1eddng bi\u1ebfn \u0111\u1ed5i theo th\u1eddi gian. Trong ch\u1ea5t d\u1eabn ho\u00e0n to\u00e0n \u0111\u00e3 kh\u00f4ng c\u00f3 \u0111i\u1ec7n tr\u01b0\u1eddng, th\u1ebf th\u00ec trong n\u00f3 c\u0169ng kh\u00f4ng th\u1ec3 t\u1ed3n t\u1ea1i t\u1eeb tr\u01b0\u1eddng bi\u1ebfn \u0111\u1ed5i theo th\u1eddi gian.<\/p>\n\n\n\n
N\u0103m 1911, t\u1ea1i m\u1ed9t ph\u00f2ng th\u1ef1c nghi\u1ec7m \u1edf H\u00e0 Lan do gi\u00e1o s\u01b0 Onnes l\u00e3nh \u0111\u1ea1o, m\u1ed9t ph\u00e1t hi\u1ec7n l\u1edbn lao l\u00e0m cho nh\u00e2n vi\u00ean nghi\u00ean c\u1ee9u r\u1ea5t s\u1eedng s\u1ed1t. H\u1ecd \u0111\u00e3 nh\u1eadn th\u1ea5y, \u1edf g\u1ea7n nhi\u1ec7t \u0111\u1ed9 4,2 K (kho\u1ea3ng \u2013269\u00b0C), \u0111i\u1ec7n tr\u1edf c\u1ee7a thu\u1ef7 ng\u00e2n \u0111\u1ed9t nhi\u00ean bi\u1ebfn m\u1ea5t. V\u1ec1 sau l\u1ea1i ph\u00e1t hi\u1ec7n, khi nhi\u1ec7t \u0111\u1ed9 \u1edf 3,8 K (kho\u1ea3ng \u2013270\u00b0C), \u0111i\u1ec7n tr\u1edf c\u1ee7a thi\u1ebfc c\u0169ng kh\u00f4ng c\u00f2n n\u1eefa. L\u00fac b\u1ea5y gi\u1edd h\u1ecd g\u1ecdi lo\u1ea1i tr\u1ea1ng th\u00e1i d\u1eabn \u0111i\u1ec7n \u0111\u1eb7c th\u00f9 \u1ea5y l\u00e0 tr\u1ea1ng th\u00e1i si\u00eau d\u1eabn. Ch\u1ea5t d\u1eabn \u0111i\u1ec7n th\u1ec3 hi\u1ec7n tr\u1ea1ng th\u00e1i si\u00eau d\u1eabn \u1edf nhi\u1ec7t \u0111\u1ed9 r\u1ea5t th\u1ea5p t\u1ee9c l\u00e0 ch\u1ea5t si\u00eau d\u1eabn.<\/p>\n\n\n\n
Ch\u1ea5t si\u00eau d\u1eabn c\u00f3 ph\u1ea3i l\u00e0 ch\u1ea5t d\u1eabn \u0111i\u1ec7n ho\u00e0n to\u00e0n kh\u00f4ng? X\u00e9t t\u1eeb \u0111\u1eb7c \u0111i\u1ec3m \u0111i\u1ec7n tr\u1edf b\u1eb1ng kh\u00f4ng, ch\u1ea5t si\u00eau d\u1eabn kh\u00f4ng c\u00f3 g\u00ec kh\u00e1c v\u1edbi ch\u1ea5t d\u1eabn \u0111i\u1ec7n ho\u00e0n to\u00e0n. Tuy nhi\u00ean, c\u00e1c nh\u00e0 khoa h\u1ecdc th\u00f4ng qua th\u1ef1c nghi\u1ec7m \u0111\u00e3 cho th\u1ea5y ch\u1ea5t si\u00eau d\u1eabn c\u00f3 m\u1ed9t lo\u1ea1i t\u00ednh ch\u1ea5t r\u1ea5t \u0111\u1eb7c bi\u1ec7t. Lo\u1ea1i t\u00ednh ch\u1ea5t n\u00e0y g\u1ecdi l\u00e0 t\u00ednh kh\u00e1ng t\u1eeb ho\u00e0n to\u00e0n. T\u00ednh ch\u1ea5t n\u00e0y ch\u1ea5t d\u1eabn \u0111i\u1ec7n ho\u00e0n to\u00e0n kh\u00f4ng c\u00f3.<\/p>\n\n\n\n
\u0110\u01b0a m\u1ed9t nam ch\u00e2m c\u00f3 t\u1eeb t\u00ednh r\u1ea5t m\u1ea1nh \u0111\u1ebfn g\u1ea7n ch\u1ea5t d\u1eabn, ch\u1ea5t d\u1eabn d\u1ec5 b\u1ecb nam ch\u00e2m h\u00fat l\u1ea1i. \u0110\u00f3 l\u00e0 v\u00ec ch\u1ea5t d\u1eabn ch\u1ecbu \u1ea3nh h\u01b0\u1edfng c\u1ee7a nam ch\u00e2m n\u00ean c\u0169ng c\u00f3 t\u1eeb t\u00ednh, g\u1ecdi l\u00e0 t\u1eeb ho\u00e1. Tuy nhi\u00ean, khi \u0111\u01b0a th\u1ecfi t\u1eeb \u0111\u1ebfn g\u1ea7n v\u1eadt si\u00eau d\u1eabn th\u00ec nam ch\u00e2m l\u1ea1i ph\u1ea3i ch\u1ecbu m\u1ed9t l\u1ef1c c\u1ea3n r\u1ea5t l\u1edbn. N\u1ebfu \u0111\u1eb7t ch\u1ea5t si\u00eau d\u1eabn l\u00ean m\u1eb7t b\u00e0n, khi cho nam ch\u00e2m \u0111\u1ebfn g\u1ea7n ch\u1ea5t si\u00eau d\u1eabn t\u1eeb ph\u00eda tr\u00ean xu\u1ed1ng, l\u1ef1c c\u1ea3n \u0111\u1ed1i v\u1edbi nam ch\u00e2m l\u1edbn \u0111\u1ebfn n\u1ed7i c\u00f3 th\u1ec3 c\u00e2n b\u1eb1ng v\u1edbi tr\u1ecdng l\u1ef1c c\u1ee7a nam ch\u00e2m, l\u00e0m cho nam ch\u00e2m b\u1ecb treo n\u1ed5i b\u00ean tr\u00ean ch\u1ea5t si\u00eau d\u1eabn. \u0110\u00f3 t\u1ee9c l\u00e0 hi\u1ec7n t\u01b0\u1ee3ng treo n\u1ed5i t\u1eeb (hay hi\u1ec7u \u1ee9ng si\u00eau d\u1eabn n\u1eb7ng kh\u00f4ng ti\u1ebfp x\u00fac). Nguy\u00ean nh\u00e2n sinh ra hi\u1ec7n t\u01b0\u1ee3ng \u0111\u00f3 l\u00e0 \u1edf ch\u1ed7 ch\u1ea5t si\u00eau d\u1eabn kh\u00f4ng b\u1ecb t\u1eeb ho\u00e1. N\u00f3 c\u00f3 t\u00ednh kh\u00e1ng t\u1eeb r\u1ea5t m\u1ea1nh (ch\u1ea5t si\u00eau d\u1eabn \u0111\u1ea9y to\u00e0n b\u1ed9 t\u1eeb th\u00f4ng). Trong ch\u1ea5t d\u1eabn ho\u00e0n to\u00e0n, t\u1eeb tr\u01b0\u1eddng m\u1ed9t khi \u0111\u01b0\u1ee3c sinh ra th\u00ec kh\u00f4ng th\u1ec3 n\u00e0o t\u0103ng l\u00ean ho\u1eb7c m\u1ea5t \u0111i. Nh\u01b0ng trong ch\u1ea5t si\u00eau d\u1eabn, ho\u00e0n to\u00e0n kh\u00f4ng c\u00f3 t\u1eeb tr\u01b0\u1eddng n\u00e0o xu\u1ea5t hi\u1ec7n c\u1ea3. Cho d\u00f9 trong ch\u1ea5t d\u1eabn v\u1ed1n c\u00f3 t\u1eeb tr\u01b0\u1eddng t\u1ed3n t\u1ea1i, khi bi\u1ebfn th\u00e0nh ch\u1ea5t si\u00eau d\u1eabn r\u1ed3i th\u00ec t\u1eeb tr\u01b0\u1eddng li\u1ec1n b\u1ecb \u0111\u1ea9y t\u1ea5t c\u1ea3 ra ngo\u00e0i ch\u1ea5t si\u00eau d\u1eabn. N\u1ebfu \u0111\u1eb7t m\u1ed9t t\u1eeb tr\u01b0\u1eddng v\u00e0o b\u00ean ngo\u00e0i ch\u1ea5t si\u00eau d\u1eabn th\u00ec t\u1eeb tr\u01b0\u1eddng \u1ea5y kh\u00f4ng sao \u0111i v\u00e0o trong ch\u1ea5t si\u00eau d\u1eabn \u0111\u01b0\u1ee3c. V\u00ec v\u1eady, x\u00e9t v\u1ec1 m\u1eb7t t\u00ednh ch\u1ea5t kh\u00e1ng t\u1eeb, ch\u1ea5t si\u00eau d\u1eabn kh\u00f4ng ph\u1ea3i l\u00e0 ch\u1ea5t d\u1eabn ho\u00e0n to\u00e0n. N\u00f3 l\u00e0 m\u1ed9t tr\u1ea1ng th\u00e1i m\u1edbi c\u1ee7a ch\u1ea5t d\u1eabn t\u1ed3n t\u1ea1i \u1edf nhi\u1ec7t \u0111\u1ed9 c\u1ef1c th\u1ea5p.<\/p>\n\n\n\n
L\u1ee3i d\u1ee5ng hi\u1ec7u \u1ee9ng t\u00ednh kh\u00e1ng t\u1eeb c\u1ee7a ch\u1ea5t si\u00eau d\u1eabn, hi\u1ec7n nay ng\u01b0\u1eddi ta \u0111\u00e3 ch\u1ebf t\u1ea1o \u0111\u01b0\u1ee3c \u0111o\u00e0n t\u00e0u ho\u1ea3 treo n\u1ed5i t\u1eeb. \u0110o\u00e0n t\u00e0u n\u00e0y ch\u1ea1y b\u00ean tr\u00ean \u0111\u01b0\u1eddng ray, kh\u00f4ng c\u00f3 l\u1ef1c ma s\u00e1t gi\u1eefa \u0111\u01b0\u1eddng ray v\u00e0 b\u00e1nh xe nh\u01b0 lo\u1ea1i t\u00e0u ho\u1ea3 th\u00f4ng th\u01b0\u1eddng, t\u1ed1c \u0111\u1ed9 ch\u1ea1y t\u00e0u c\u00f3 th\u1ec3 t\u0103ng l\u00ean r\u1ea5t cao.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: \u0110i\u1ec7n tr\u1edf; Ch\u1ea5t d\u1eabn ho\u00e0n to\u00e0n; Ch\u1ea5t si\u00eau d\u1eabn; T\u00ednh kh\u00e1ng t\u1eeb; Treo n\u1ed5i t\u1eeb.<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
C\u00e1i danh t\u1eeb ch\u1ea5t d\u1eabn (\u0111i\u1ec7n) kh\u00f4ng xa l\u1ea1 g\u00ec \u0111\u1ed1i v\u1edbi ch\u00fang ta c\u1ea3. H\u1eb1ng ng\u00e0y, khi ch\u00fang ta b\u1eadt ra\u0111i\u00f4 hay tivi, ch\u1ea5t d\u1eabn li\u1ec1n hi\u1ec7n r\u00f5 ngay, chuy\u1ec3n bi\u1ebfn t\u00edn hi\u1ec7u \u0111i\u1ec7n th\u00e0nh \u00e2m nh\u1ea1c du d\u01b0\u01a1ng v\u00e0 h\u00ecnh \u1ea3nh t\u01b0\u01a1i \u0111\u1eb9p. S\u1edf d\u0129 ch\u1ea5t d\u1eabn c\u00f3 \u0111\u01b0\u1ee3c t\u00ednh n\u0103ng d\u1eabn \u0111i\u1ec7n […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[15,7],"tags":[],"class_list":["post-5840","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-vat-ly"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5840","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=5840"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5840\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=5840"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=5840"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=5840"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}