VERY LOW FREQUENCIES INTERNAL FRICTION MEASUREMENTS OF ICE Ih

J. Tatibouet, J. Perez, R. Vassoille
1981 Le Journal de Physique Colloques  
A b s t r a c t Very low f r e q u e n c i e s i n t e r n a l f r i c t i o n measurement ( 1 -10' 4 -~z ) i n i c e p e r m i t t e d t o i n c r e a s e t h e knowledge of t h e i n t e r n a l f r i c t i o n of i c e , e s p e c i a l l y t h e r e l a x a t i o n phenomenon. The a c t i v a t i o n energy of t h e r e l a x a t i o n i s 0.25 eV, a c a r a c t e r i st i c v a l u e of t h e m i g r a t i o n of r o t a t i o n a , l d e f e c t s . I t f o l l o w s a C u r i e Law.
more » ... iments a f t e r d i f f e r e n t c o o l i n g r a t e p u t i n evidence t h e r o l e of i n t r i n s i c d e f e c t s . 1 . I n t r o d u c t i o n -U n t i l t o day i n t e r n a l f r i c t i o n of I c e Ih h a s been s t u d i e d i n t h e k i l o h e r t z [ l , 2 , 3 3 and H e r t z 141 f r e q u e n c i e s r a n g e s . bleasurenient have a l s o been made by u l t r a s o n i c waves t e c h n i c s f5]. Experiments made on simple c r y s t a l s a t 1 H e r t z between 100 and 273 K show 3 noteworthy f e a t u r e s . i ) a r e l a x a t i o n peak observed by o t h e r s a u t h o r s a t h i g h e r frequenc i e s [ I , 2, 33. i i ) an i n c r e a s e of t h e i n t e r n a l f r i c t i o n a t h i g h t e m p e r a t u r e (230-273 K ) . i i i ) A t h i g h t e m p e r a t u r e , i n t e r n a l f r i c t i o n becomes amplitude dependant. The h i g h e r t h e t e m p e r a t u r e , t h e more p r o n o u n c e d . t h i s amplitude dependence. .High t e m p e r a t u r e phenomena a r e a t t r i b u t e d t o t h e movement of d i s l o c at i o n s u n d e r t h e c y c l i c s t r e s s and s e v e r a l i n t e r~r e t a t i o n s have been y e t developped 1 6 , 71. Bass[8] h a s i n t e r p r e t e d t h e mechanical r e l a x a t i o n by a rearrangement o f w a t e r m o l e c u l e s w i t h t h e h e l p of t h e r o~a t i o n n a l ( o r Bjerrum) d e f e c t s , i n r e s p e c t of t h e Bernal and Fowler r u l e s . From an analogous way, Gosar 19) h a s c o n s i d e r e d t h a t each w a t e r molecule i s a p o i n t d e f e c t i n t h e i c e l a t t i c e , and h a s ;:eneralized t h e model of Bass by i n t r o d u c i n g t h e concept of e l a s t i c d i p o l e s p r e v i o u s l y developped. He c a l c u l a t e d t h e f r e e e n e r g y of t h e c r y s t a l by i n t r o d u c i n g t h e p r o t o n d e s o r d e r e n t r o p y w i t h t h e h e l p of g r a p h t h e o r y a s Nagle 110) d i d i t f o r t h e d i e l e c t r i c r e l a x a t i o n . Article published online by EDP Sciences and available at http://dx.
doi:10.1051/jphyscol:1981582 fatcat:hsyhhirxzzht5dk5r3udy3sx2m