Low-temperature studies of magnetic phases of the interfacial layers for Co/Ge(100) and Co/Ge(111) films

Jyh-Shen Tsay, C. W. Su, C. H. Hwang, Y. D. Yao

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Magnetic phases of the interfacial layers were comparatively investigated for CoGe (100) and CoGe (111) films thinner than 13 ML using surface magneto-optic Kerr effect technique. CoGe (100) films are nonferromagnetic up to 12 ML as deposited and measured at 300 K. A transition from nonferromagnetism to ferromagnetism occurs upon cryogenic treatments. Systematic investigations of the magnetic properties for CoGe (100) reveal a magnetic phase diagram. The boundary between nonferromagnetic and ferromagnetic phases was experimentally determined to be from below 150 K to above 300 K as the cobalt thickness increases from 9 to 13 ML. This behavior is consistent with the thickness-dependent scaling law of the Curie temperature for a thin film system. Because of the difference of the densities of surface atoms, the different thickness of the formed interfacial compounds could explain the shift of the phase boundary to higher Co thickness side as compared to the CoGe (111) system. In addition, the critical exponent Β in the power law relationship of magnetization for CoGe (100) films lies close to the value expected by the three-dimensional Heisenberg model, while the critical exponent of CoGe (111) is close to the value of the two-dimensional XY model. The different behaviors of the magnetic transition are attributed to the different interfacial structures.

Original languageEnglish
Pages (from-to)781-784
Number of pages4
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Volume23
Issue number4
DOIs
Publication statusPublished - 2005 Jul 1

Fingerprint

Thin films
Magnetooptical effects
Ferromagnetism
Scaling laws
Phase boundaries
Curie temperature
Cobalt
Cryogenics
Phase diagrams
Magnetization
Magnetic properties
exponents
Atoms
Temperature
magneto-optics
thin films
Kerr effects
two dimensional models
scaling laws
ferromagnetism

ASJC Scopus subject areas

  • Surfaces, Coatings and Films
  • Surfaces and Interfaces
  • Physics and Astronomy (miscellaneous)

Cite this

Low-temperature studies of magnetic phases of the interfacial layers for Co/Ge(100) and Co/Ge(111) films. / Tsay, Jyh-Shen; Su, C. W.; Hwang, C. H.; Yao, Y. D.

In: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, Vol. 23, No. 4, 01.07.2005, p. 781-784.

Research output: Contribution to journalArticle

@article{0dc3a355b6f94e2e8f5db03ac509896f,
title = "Low-temperature studies of magnetic phases of the interfacial layers for Co/Ge(100) and Co/Ge(111) films",
abstract = "Magnetic phases of the interfacial layers were comparatively investigated for CoGe (100) and CoGe (111) films thinner than 13 ML using surface magneto-optic Kerr effect technique. CoGe (100) films are nonferromagnetic up to 12 ML as deposited and measured at 300 K. A transition from nonferromagnetism to ferromagnetism occurs upon cryogenic treatments. Systematic investigations of the magnetic properties for CoGe (100) reveal a magnetic phase diagram. The boundary between nonferromagnetic and ferromagnetic phases was experimentally determined to be from below 150 K to above 300 K as the cobalt thickness increases from 9 to 13 ML. This behavior is consistent with the thickness-dependent scaling law of the Curie temperature for a thin film system. Because of the difference of the densities of surface atoms, the different thickness of the formed interfacial compounds could explain the shift of the phase boundary to higher Co thickness side as compared to the CoGe (111) system. In addition, the critical exponent Β in the power law relationship of magnetization for CoGe (100) films lies close to the value expected by the three-dimensional Heisenberg model, while the critical exponent of CoGe (111) is close to the value of the two-dimensional XY model. The different behaviors of the magnetic transition are attributed to the different interfacial structures.",
author = "Jyh-Shen Tsay and Su, {C. W.} and Hwang, {C. H.} and Yao, {Y. D.}",
year = "2005",
month = "7",
day = "1",
doi = "10.1116/1.1861936",
language = "English",
volume = "23",
pages = "781--784",
journal = "Journal of Vacuum Science and Technology A",
issn = "0734-2101",
publisher = "AVS Science and Technology Society",
number = "4",

}

TY - JOUR

T1 - Low-temperature studies of magnetic phases of the interfacial layers for Co/Ge(100) and Co/Ge(111) films

AU - Tsay, Jyh-Shen

AU - Su, C. W.

AU - Hwang, C. H.

AU - Yao, Y. D.

PY - 2005/7/1

Y1 - 2005/7/1

N2 - Magnetic phases of the interfacial layers were comparatively investigated for CoGe (100) and CoGe (111) films thinner than 13 ML using surface magneto-optic Kerr effect technique. CoGe (100) films are nonferromagnetic up to 12 ML as deposited and measured at 300 K. A transition from nonferromagnetism to ferromagnetism occurs upon cryogenic treatments. Systematic investigations of the magnetic properties for CoGe (100) reveal a magnetic phase diagram. The boundary between nonferromagnetic and ferromagnetic phases was experimentally determined to be from below 150 K to above 300 K as the cobalt thickness increases from 9 to 13 ML. This behavior is consistent with the thickness-dependent scaling law of the Curie temperature for a thin film system. Because of the difference of the densities of surface atoms, the different thickness of the formed interfacial compounds could explain the shift of the phase boundary to higher Co thickness side as compared to the CoGe (111) system. In addition, the critical exponent Β in the power law relationship of magnetization for CoGe (100) films lies close to the value expected by the three-dimensional Heisenberg model, while the critical exponent of CoGe (111) is close to the value of the two-dimensional XY model. The different behaviors of the magnetic transition are attributed to the different interfacial structures.

AB - Magnetic phases of the interfacial layers were comparatively investigated for CoGe (100) and CoGe (111) films thinner than 13 ML using surface magneto-optic Kerr effect technique. CoGe (100) films are nonferromagnetic up to 12 ML as deposited and measured at 300 K. A transition from nonferromagnetism to ferromagnetism occurs upon cryogenic treatments. Systematic investigations of the magnetic properties for CoGe (100) reveal a magnetic phase diagram. The boundary between nonferromagnetic and ferromagnetic phases was experimentally determined to be from below 150 K to above 300 K as the cobalt thickness increases from 9 to 13 ML. This behavior is consistent with the thickness-dependent scaling law of the Curie temperature for a thin film system. Because of the difference of the densities of surface atoms, the different thickness of the formed interfacial compounds could explain the shift of the phase boundary to higher Co thickness side as compared to the CoGe (111) system. In addition, the critical exponent Β in the power law relationship of magnetization for CoGe (100) films lies close to the value expected by the three-dimensional Heisenberg model, while the critical exponent of CoGe (111) is close to the value of the two-dimensional XY model. The different behaviors of the magnetic transition are attributed to the different interfacial structures.

UR - http://www.scopus.com/inward/record.url?scp=31144466855&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=31144466855&partnerID=8YFLogxK

U2 - 10.1116/1.1861936

DO - 10.1116/1.1861936

M3 - Article

VL - 23

SP - 781

EP - 784

JO - Journal of Vacuum Science and Technology A

JF - Journal of Vacuum Science and Technology A

SN - 0734-2101

IS - 4

ER -