Visualization and manipulation of magnetic domains in the quasi-two-dimensional material $\mathrm{F}{\mathrm{e}}_{3}\mathrm{GeT}{\mathrm{e}}_{2}$

Visualization and manipulation of magnetic domains in the quasi-two-dimensional material $F e_{3} GeT e_{2}$

Giang D. Nguyen, Jinhwan Lee, Tom Berlijn, Qiang Zou, Saban M. Hus, Jewook Park, Zheng Gai, Changgu Lee, and An-Ping Li

Phys. Rev. B 97, 014425 – Published 22 January 2018

Abstract

The magnetic domains in two-dimensional layered material $F e_{3} GeT e_{2}$ are studied by using a variable-temperature scanning tunneling microscope with a magnetic tip after in situ cleaving of single crystals. A stripy domain structure is revealed in a zero-field-cooled sample below the ferromagnetic transition temperature of 205 K, which is replaced by separate double-walled domains and bubble domains when cooling the sample under a magnetic field of a ferromagnetic Ni tip. The Ni tip can further convert the double-walled domain to a bubble domain pattern as well as move the Neel-type chiral bubble in submicrometer distance. The temperature-dependent evolutions of both zero-field-cooled and field-cooled domain structures correlate well with the bulk magnetization from magnetometry measurements. Atomic resolution scanning tunneling images and spectroscopy are acquired to understand the atomic and electronic structures of the material, which are further corroborated by first-principles calculations.

Received 17 August 2017
Revised 4 January 2018

DOI:https://doi.org/10.1103/PhysRevB.97.014425

Physics Subject Headings (PhySH)

Defects Magnetic domains Magnetic phase transitions Methods in magnetism Skyrmions

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Giang D. Nguyen¹, Jinhwan Lee², Tom Berlijn^1,3, Qiang Zou¹, Saban M. Hus¹, Jewook Park^1,4, Zheng Gai¹, Changgu Lee^2,5, and An-Ping Li^1,*

¹Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
²School of Mechanical Engineering, Sungkyunkwan University, Suwon, Kyonggi-do 16419, Korea
³Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
⁴Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea
⁵SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, Kyonggi-do 16419, Korea

^*apli@ornl.gov

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 97, Iss. 1 — 1 January 2018

Reuse & Permissions

Access Options

Article Available via CHORUS

Download Accepted Manuscript

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
The evolution of ZFC magnetic domains of cleaved $F e_{3} GeT e_{2}$ visualized by STM imaging with a Ni tip while increasing sample temperature from 120 to 210 K. The semitransparent overlays in (a) illustrate the magnetizations parallel (P, red color) and antiparallel (AP, blue color) to the tip magnetization. The Ni tip is kept 10 mm away from the surface when cooling from the room temperature to 120 K to avoid the effect of Ni tip stray field on the formation of the magnetic domains. During warming up, the Ni is kept $1 μ m$ away from the surface at the image corner. The scanning parameters are kept the same: $V_{s} = - 0.5 V$ , $I = 50 pA$ .
Reuse & Permissions
Figure 2
The evolution of the FC magnetic domains through varying sample temperatures between 120 and 220 K. The magnetic domains were induced by keeping the Ni tip $3 μ m$ away from the surface when cooling the sample down from the room temperature. The Ni tip is kept $1 μ m$ away from the surface at the image corner during warming up (a–d) and cooling down (h–e). The scanning parameters are kept the same of sample bias $V_{s} = - 0.5 V$ , tunneling current $I = 50 pA$ . The blue box and circle in (a) mark an example of a double-walled domain and a bubble domain, respectively. P and AP point to the domain areas with the magnetization parallel (P) and antiparallel (AP) to the tip magnetization. The dashed black circles in (c) mark the bubble domains newly converted from double-walled domains [marked by dashed black boxes in (b)] during warming from 150 to 190 K.
Reuse & Permissions
Figure 3
(a, b) STM images of magnetic domains before (a) and after (b) tip-induced conversion of a double-walled domain (marked with dashed black box) into a bubble domain (marked with dashed black circle). (c, d) STM images of a double-walled domain showing a displacement of the inner wall between the backward (c) and the forward (d) scanned images, while the outer domain wall stays the same (sample bias $V_{s} = - 0.5 V$ , tunneling current $I = 100 pA$ , temperature $T = 120 K$ ). (e) Line profile across the outer walls of double-walled domain along the rectangle in (b). (f) Schematic spin structure of a Neel domain wall with respect to the STM tip magnetization ${\vec{M}}_{T}$ .
Reuse & Permissions
Figure 4
(a) Field-dependent magnetization plot at 80 and 5 K. The external field is applied in $H ∥ x y$ and $H ∥ z$ directions, respectively. Inset is the zoom-in section showing coercive field for $F e_{3} GeT e_{2}$ at 80 K. (b) Magnetization as a function of temperature. The applied field (1 kOe) is in $H ∥ x y$ and $H ∥ z$ .
Reuse & Permissions
Figure 5
(a) Atomically resolved STM image acquired with a W tip on cleaved $F e_{3} GeT e_{2}$ ( $V_{s} = - 0.5 V$ , $I = 100 pA$ , $T = 120 K$ ). (b) Density functional theory results showing atomic displacements (indicated by red arrows) induced by an Fe(2) vacancy in a $\sqrt 3 \times \sqrt 3$ supercell.
Reuse & Permissions
Figure 6
The schematic micromagnetic domain structure of the FC double-walled domain and bubble domain. The blue and red colors represent two opposite magnetization directions which are antiparallel (blue) and parallel (red) to the tip magnetization, respectively.
Reuse & Permissions

Physical Review B

covering condensed matter and materials physics

Visualization and manipulation of magnetic domains in the quasi-two-dimensional material $F e_{3} GeT e_{2}$

Giang D. Nguyen, Jinhwan Lee, Tom Berlijn, Qiang Zou, Saban M. Hus, Jewook Park, Zheng Gai, Changgu Lee, and An-Ping Li

Phys. Rev. B 97, 014425 – Published 22 January 2018

Abstract

Physics Subject Headings (PhySH)

Authors & Affiliations

Article Text (Subscription Required)

Supplemental Material (Subscription Required)

References (Subscription Required)

Issue

Access Options

Physical Review B

covering condensed matter and materials physics

Visualization and manipulation of magnetic domains in the quasi-two-dimensional material Fe3GeTe2

Giang D. Nguyen, Jinhwan Lee, Tom Berlijn, Qiang Zou, Saban M. Hus, Jewook Park, Zheng Gai, Changgu Lee, and An-Ping Li

Phys. Rev. B 97, 014425 – Published 22 January 2018

Abstract

Physics Subject Headings (PhySH)

Authors & Affiliations

Article Text (Subscription Required)

Supplemental Material (Subscription Required)

References (Subscription Required)

Issue

Access Options

Authorization Required

Other Options

Download & Share

Images

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Log In

Search

Article Lookup

Paste a citation or DOI

Enter a citation

Visualization and manipulation of magnetic domains in the quasi-two-dimensional material $F e_{3} GeT e_{2}$