Experimental Methods

In-House Setups

Hall measurement system with temperature control setups: T1~T3

Hall measurement (T1)

Owned by UOS physics dept.

Permanent magnets with 0.56 T, I = 10 nA ~ 20 mA

Duration = 150 sec (PC control) or Manual

Spring clip sample boards (soldering free)

Manufactured by Ecopia

(2013.07.16)

High temperature chamber with 4 probe tips (T2)

Temperature: 80 K ~800 K

(<300 K with LN2 flow and >300 K with heater, 10 K)

Pressure: >1x10^-2 torr (a rotary pump)

Windows at top and bottom of the sample

Model: HFS600E-PB4

Manufactured by Linkam and imported by Visionus

(2013.07.16)

Low temperature closed cycle refrigerator with 8 probe wires (T3)

Borrowed from Prof. E. Choi

Temperature: 8 K ~ 350 K

(8 K(sample) and 7 K(cold finger) within 2 hours)

Pressure: <1x10^-3 torr (a rotary pump)

PC control with Labview (Yong Hyun Kim, 2013-08-30)

Model: CCS model 22 (Janis) + Compressor model 8200 (ASM) + Lakeshore 330

Manufactured by Janis and imported by Woosin Cryovac

Contact Sungwoo Instruments for refill He gas in the refrigerator

Contact ASK corp for other symptoms

(before 2012)

In-House Synthesis

MBE (M1): Chalcogenide (Se, Te)

-ebeam evaporator cells (~3000'C, Focus GmbH)

-thermal effusion cells (~1000'C)

-RHEED (Pascal)

(2014.01.16~)

MBE (M2): Chalcogenide (Se, S)

-ebeam evaporator cells (~3000'C, Focus GmbH)

-thermal effusion cells (~1000'C)

-RHEED (Pascal)

(2020.03.01~)

Evaporator (E1): Chalcogenide (Te)

Sample Pressure: >2x10^-8 torr

E-beam (7 cc, 4 pockets)

PC controlled growth

Manufactured by Korea vacuum tech

(2013.10.24) (modified at 2016.02.05)

User Facilities (External)

ARPES(angle-resolved photoemission spectroscopy), BL10.0.2, ALS, LBNL, Berkeley, USA: user facility (since 2018.07.01)

https://als.lbl.gov/beamlines/10-0-1/

https://sites.google.com/lbl.gov/bl10hers/

ARPES(angle-resolved photoemission spectroscopy), BL7.0.2, ALS, LBNL, Berkeley, USA: user facility (since 2015.01.01)

Maestro beamline (BL 7.0.2), Advanced Light Source, Berkeley National Lab

http://ssg.als.lbl.gov/ssgbeamlines/beamline7-0-1-2/

XMCD, APS, Argonne National Lab, Chicago, USA: user facility (since 2018.03.20)

4-ID-C beamline, Advance Photon Source

BL: https://www.aps.anl.gov/Sector-4/4-ID-C/Instrumentation

Sample holder: https://www.aps.anl.gov/sites/default/files/APS-Uploads/SECTOR4/Octupole_Specs.pdf

XMCD, PLS, Pohang, Korea: user facility (since 2016.10.18)

2A1 beamline, Pohang Light Source

ARPES, PLS, Pohang, Korea: user facility (since 2013.01.01)

4A1 beamline, Pohang Light Source, POSTECH

- Insertion device: Undulator

- Beam energy : 25 ~ 1000 eV

- Energy resolution : E/ΔE = 10000 ~ 30000

- Photon count : > 10^10 photons/sec·(0.1% bandwidth)

- Beam size : 10 μm × 10 μm

- Electron analyser: Scienta R4000

- LEED, Sputter gun

- Open cycle cryostat

- Main chamber-Preparation ch.-Loadlock ch.

http://pal.postech.ac.kr/bl/4A1/