Kink velocities on dislocations in ice

Frost, H. Robert; Goodman, D. J.; Ashby, MF

doi:10.1080/14786437608221927

Cited by 34 publications

(22 citation statements)

References 7 publications

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“…But it should be noted that dislocation glide along the basal plane in ice crystals also needs the diffusion of protons (proton rearrangements) due to the special point defects (proton disorder) in ice crystals. Previous works [39][40][41][42] indicated that disorder of the protons in ice constitutes in principle an obstacle to the glide of dislocations. Fig.…”

Section: Evaluation Of the Two Rate-controlling Mechanismsmentioning

confidence: 99%

An evaluation of the rate-controlling flow process in Newtonian creep of polycrystalline ice

Song

2008

Materials Science and Engineering: A

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Section: Evaluation Of the Two Rate-controlling Mechanismsmentioning

confidence: 99%

An evaluation of the rate-controlling flow process in Newtonian creep of polycrystalline ice

Song

2008

Materials Science and Engineering: A

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“…Glen's hypoth esis has been quantitatively improved by Perez and others ( 19 75 ) , Whitworth and others ( 1976) a nd Frost and others ( 1976) . In all cases, assuming a kink model , th e following relation was found for dislocation velocity:…”

Section: Introductionmentioning

confidence: 99%

“…The nature of obstacles to dislocation glide has to be identified . I t has been proposed by G len (1968) that th e disorder of th e protons on the O -H-O bonds in ice can be such an obstacle.Glen's hypoth esis has been quantitatively improved by Perez and others ( 19 75 ) , Whitworth and others ( 1976) a nd Frost and others ( 1976) . In all cases, assuming a kink model , th e following relation was found for dislocation velocity:…”

mentioning

confidence: 99%

Cooperative Movement of H2O Molecules and Dynamic Behaviour of Dislocations in Ice Ih

1978

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AUSTRACT. A new m od e l o f d islocations glid e in ice Ih is proposed . In developing this m odel certain assumpti o ns a re made : (i) dislocations have a non-c rystallin e exte nd ed core, a nd (ii ) tra nsitions occur through coope ra ti ve movem e nts of H 2 0 molecules in th e core of dis lo ca tions. A rela tion be twee n the velocity V d of linea r d e fects a nd shea r stress 'T or tempera ture T is obta in cd. This relation shows that V d vari es linearly with 'T at low values or 'T a nd (or) T but vari es more ra pidl y at high e r stresses; this non-l in earity is more pronoun ced the highcr the te mpe ra ture. Such res ults a re in agreem e nt wi th expcrime nta l data. RESUME. N fouvement coop.ratif des lIlo/icu/es H 2 0 et comportement dYllamiqlle des dislocatiolls dans la glace Ill. U n nouvea u m od ele de glissem e nt d es d islocations d a ns la glace Ih est d eveioppe it partir d es d e ux h ypotheses sui va ntes: (i) les disloca tions presentent un coeur e te ndu de matie re non cristal line, e t (ii ) d es transitions entre diffe r e ntes configura tions se produ isen t grace it d es mouvem e nts coopera tifs d e mol ecules d'ea u . ! ous obte nons une relatio n e ntre la vitesse Vd des disloca tions la contrainte 'T et la tempe rature T; celle-ci montre que V d varie lin eairement avec 'T a ux faibles valeurs de 'T e t (ou ) de T. Cette varia tion est plus rapide aux rortes contraintes e t la non-lin eari te es t d' a utant plus impo rtante quc la tempe rature est elevee. Cette d escription es t bien e n accord a vec Ies res ulta ts pOl·ta nt sur les m esures direc tes d e V d . ZUSAMMENFA SSUNG . Kooperative Bewegullg von H 2 0-Nfolekalen und dY llamisches Verhalten von VersetzllTlgen inEis Ill. Ein ne ues Mod ell d e r V erse tzungsgleitung in Eis Ih wird vorgeschlagen. Dieses M odell wird entwickelt unte r d er Ann a hm e, dass (i) Verse tzunge n einen a usgedehnte n nicht-krista llin e n K ern besitzen und (ii ) Ubergange durch kooperati ve Bewegung vo n H 2 0-MolekLil e n im Versetzungske rn e rfo lgen. Man erha lt ein e Bez iehung zwische n d er Geschwindigke it Vd d er lin ea ren F e hlstellen und d e r S c hubspannung 'T oder de r T e mpera tur T. Diese Bezi ehung zc ig t, d ass sich Vd lin ea r mi t 'T a nden bei ni edri ge n vVerten von 'T und (ode r ) T , aber dass es sich bei hohen Spannungen starker ande rt. Di esc Nichtlin carita t ist umso bedeutender , j e h oller die T e mpe ratur ist. Diese E rg e bnisse stimmen mit experimentel le n \ Verten liberein . I NTROD UCTIONAttempts were made several years ago to m easure the disloca tion velocity in ice Ih; it has been shown that its value, which depends on te mpera ture and on stress, is as low as 10-8 to 10-5 m S-I . The nature of obstacles to dislocation glide has to be identified . I t has been proposed by G len (1968) that th e disorder of th e protons on the O -H-O bonds in ice can be such an obstacle.Glen's hypoth esis has been quantitatively improved by Perez and others ( 19 75 ) , Whitworth and others ( 1976) a nd Fro...

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“…(6) deformation of the elastic medium, a is the external stress, Q is the Burger's vector~ h is the height of the kink, and a is the distance between two neighboring sites. The third term in (1) describes the resonance between states Ip> and Ip+l> which leads to the kink tunneling.…”

Section: Quantum Mechanical Formulation Of Kink Velocity In Icementioning

confidence: 99%

“…The last term in (1) represents the interaction of the kink with a. The third term can be considered as a small perturbation to the kink motion;…”

Section: Quantum Mechanical Formulation Of Kink Velocity In Icementioning

confidence: 99%

Quantum mechanical approach to the velocity of dislocations in ice

Forouhi¹,

Bloomer²

1978

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Kink velocities on dislocations in ice

Cited by 34 publications

References 7 publications

An evaluation of the rate-controlling flow process in Newtonian creep of polycrystalline ice

An evaluation of the rate-controlling flow process in Newtonian creep of polycrystalline ice

Cooperative Movement of H2O Molecules and Dynamic Behaviour of Dislocations in Ice Ih

Quantum mechanical approach to the velocity of dislocations in ice

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