title: Extended point defects in crystalline materials: Ge and Si.
abstract: B diffusion measurements are used to probe the basic nature of self-interstitial point defects in Ge. We find two distinct self-interstitial forms--a simple one with low entropy and a complex one with entropy ∼30  k at the migration saddle point. The latter dominates diffusion at high temperature. We propose that its structure is similar to that of an amorphous pocket--we name it a morph. Computational modeling suggests that morphs exist in both self-interstitial and vacancylike forms, and are crucial for diffusion and defect dynamics in Ge, Si, and probably many other crystalline solids.
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: N E B
authors.initials: NE
authors.lastname: Cowern
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Simdyankin
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Ahn
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: N S
authors.initials: NS
authors.lastname: Bennett
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors.forename: J P
authors.initials: JP
authors.lastname: Goss
authors.affiliation: CEA, LETI, Minatec Campus, 38054 Grenoble, France.
authors.forename: J-M
authors.initials: JM
authors.lastname: Hartmann
authors.affiliation: ST Microelectronics, 850 rue Jean Monnet, 38920 Crolles, France.
authors.forename: A
authors.initials: A
authors.lastname: Pakfar
authors.affiliation: Mattson Thermal Products GmbH, Daimlerstrasse 10, 89160 Dornstadt, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Hamm
authors.affiliation: Probion Analysis, 37 rue de Fontenay, 92220 Bagneux, France.
authors.forename: J
authors.initials: J
authors.lastname: Valentin
authors.affiliation: CNR-IMM-MATIS and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, 35131 Padova, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Napolitani
authors.affiliation: CNR-IMM-MATIS and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, 35131 Padova, Italy.
authors.forename: D
authors.initials: D
authors.lastname: De Salvador
authors.affiliation: CNR-IMM-MATIS and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Bruno
authors.affiliation: CNR-IMM-MATIS and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Mirabella