SPring-8, the large synchrotron radiation facility

Inquiry number

SOL-0000000866

Beamline

BL39XU (X-ray Absorption and Emission Spectroscopy)

Scientific keywords

A. Sample category	inorganic material
B. Sample category (detail)	magnetic material
C. Technique	absorption and its secondary process
D. Technique (detail)	MCD, LD
E. Particular condition	polarization (circular), magnetic field (< 2 T), room temperature
F. Photon energy	X-ray (4-40 keV)
G. Target information	spin/magnetism

Industrial keywords

level 1---Application area	storage device
level 2---Target	HD,MO
level 3---Target (detail)	magnetic layer, magnetic head, spin valve
level 4---Obtainable information	magnetic moment, magnetic anisotropy, interface magnetic structure
level 5---Technique	XMCD

Classification

A80.14 magnetic materials, M40.30 XMCD

Body text

Element-specific magnetometry is a unique technique to study magnetism of a particular element in the sample. Using this technique, one can measure magnetization of the specific layers of layered magnetic films containing different magnetic elements. Magnetization of buried layers is probed with a same sensitivity as for the surface layer, using high-energy X-rays of a penetration depth as large as a few microns.
The figure shows the element-specific magnetization curves of Gd and Fe of a [Gd(2 nm)/Fe(2 nm)]₅₀ multilayer. These data indicate that the magnetic moments of Gd and Fe layers couple antiferromagnetically, and the shape of the hysteresis loops and the coercive force values are quite different from the magnetization of entire sample.

Fig. Element-specific magnetization curves in a [Gd(2 nm)/Fe(2 nm)]₅₀ multilayer.

[ A. Koizumi, M. Takagaki, M. Suzuki, N. Kawamura and N. Sakai, Physical Review B 61, R14909-R14912 (2000), Fig. 2,
©2000 American Physical Society ]

Source of the figure

Original paper/Journal article

Journal title

A. Koizumi, M. Takagaki, et al, Phys. Rev. B 61, R14909 (2000).

Figure No.

Fig. 2

Technique

An element-specific magnetization curve is measured by monitoring the difference in X-ray absorption of the sample between for right- and left-circularly polarized X-rays, as a function of the external magnetic field.  In this solution, X-ray energy was tuned to the characteristic absorption edges of Gd (7245 eV) and Fe (7111 eV) to obtain the magnetization curves for these elements.

Fig. Principle of element-specific magnetization measurement.

Source of the figure

Private communication/others

Description

鈴木基寛が作成

Required time for experimental setup

5 hour(s)

Instruments

Instrument	Purpose	Performance
Electromagnet and closed-cycle helium refrigerator	element-specific magnetometry measurements	magnetic field ±2 T, sample temerature 20-300 K
10 T superconducting magnet	XMCD spectroscopy and element-specific magnetometry measurements under high magnetic field	magnetic field ±10 T, sample temerature 1.7-300 K
Helicity-modulation XMCD	detection of XMCD signals with high accuracy and high sensitivity	XMCD signals less than 0.1% are detectable

References

Document name
A. Koizumi, M. Takagaki, M. Suzuki, N. Kawamura, and N. Sakai, Phys. Rev. B 61, R14909 (2000).
M. Takagaki, A. Koizumi, N. Kawamura, M. Suzuki, and N. Sakai, J. Phys. Soc. Jpn. 72, 245 (2003).

Related experimental techniques

VSM magnetometry, SQUID magnetometry, torque magnetometry, magnetic Kerr measurement, X-ray magnetic diffraction, X-ray magnetic reflection, XMCD

Questionnaire

The measurement was possible only in SPring-8. Impossible or very difficult in other facilities.
This solution is an application of a main instrument of the beamline.
Similar experiments account for more than 30% of the beamline's subject.

Ease of measurement

Easy

Ease of analysis

Middle

How many shifts were needed for taking whole data in the figure?

Less than one shift