**Dr. Elke Arenholz**

Advanced Light Source, Lawrence Berkeley National Laboratory,

1 Cyclotron Road Mail Stop 6R2100, Berkeley, CA 94720-8226, USA

email: earenholz@lbl.gov; phone: +1 (510) 486 4834

**[EDUCATION AND RESEARCH EXPERIENCE]{.underline}**

1.  My research program focuses on the study of magnetic systems such as
    thin films and devices, exchange biased systems, novel magnetic
    materials (complex oxides, ferromagnetic semiconductors etc.) using
    soft x rays, improving the understanding of basic effects in
    magnetic dichroism and developing instrumentation that allows
    performing unique experiments.

    Example of my research are given below (Publications are
    referenced).

**ADVANCED LIGHT SOURCE, LBNL, BERKELEY, CA** (since 02/2000)

Scientist at the magnetic spectroscopy beamlines 4.0.2 and 6.3.1

*Major research accomplishment*:

\+ X-ray magnetic circular and linear dichroism were used to improve our
understanding of exchange biased systems:\
Quantified and determined the orientation of pinned interface moments in
exchange bias\
bilayers \[1, 22\].\
Measured the sometimes controversial interface coupling unambiguously in
exchange bias\
bilayers using magnetic circular dichroism \[1, 3, 22\].\
Characterized the magnetization reversal in the ferromagnetic layer
which shows\
very rich angular dependence \[10, 12\].\
Investigated the impact of the magnetization reversal in the
ferromagnetic layer on the spin\
structure in the antiferromagnetic layer \[1, 17\].

\+ Dilute magnetic semiconductors were characterized using x-ray
magnetic dichroism leading to new insights into their magnetic and
electronic properties \[2, 4, 9, 15, 19\].

\+ By studying the strong angular dependence of x-ray magnetic linear
dichroism the basic understanding of magnetic dichroism in x-ray
absorption was significantly improved and misinterpretation in past
experiments clarified \[4 and submitted\].

\+ To make novel experiments like the study of angular effects in x-ray
magnetic linear dichroism possible an eight pole electromagnet was
developed \[11, 14\]. The system allows application of external fields
in any direction relative to the incoming x-ray beam and the sample
surface and hence new classes of magnetic dichroism experiments. By now
four systems based on our design have been built or are under
construction at the Advanced Light Source, SRS Daresbury (UK) and by
Advanced Design Consulting USA, Inc. for MAXLab (Sweden) and BESSY
(Germany). Moreover, we are currently developing similar superconducting
eight pole magnet for high field applications. This work was just funded
through an LDRD proposal.

\+ High quality magnetic dichroism spectroscopy can only be performed at
a well characterized and carefully optimized beamline. Turning the
elliptically polarizing undulator beamline 4.0.2 into a system that
allows high precision (10^4^) magnetic dichroism measurements with
variable linear and circular polarization as well as polarization
switching in a few seconds was a major undertaking.

**Materials Sciences Division, Lawrence Berkeley National Laboratory,
Berkeley, CA** (1997-2000)

Postdoctoral research fellow

*Major research accomplishment*:

\+ Surfaces of transition metal oxide single crystals as well as
transition metal thin films were prepared in situ and studied with
photoemission, x ray absorption, and x ray emission.

\+ We evaluated the influence of the core-level absorption resonance at
one atom on the photoelectron and x ray emission intensity from a core
level on a neighboring atom of another species \[31-35\].

*Advisor*: Prof. Charles S. Fadley

**Department of Physics, Freie Universität Berlin, Berlin, Germany**
(1993-1997)

Doctoral thesis, summa cum laude

*Major research accomplishments*:

\+ High quality lanthanide thin films and surfaces were prepared *in
situ* by evaporation of pure metals and subsequent condensation on
W(110) surfaces

\+ Their structural, magnetic, and electronic properties were
characterized using LEED, MOKE as well as magnetic dichroism in
photoemission and x-ray absorption.

\+ A systematic experimental and theoretical study of linear and
circular dichroism in Gd and Tb 4*f* \[51\], 5*p* \[43\], and 4*d*
\[46\] core level photoemission as well as 4*d*→4*f* \[44\] and
3*d*→4*f* resonant photoemission \[21, 37, 38\] in close collaboration
with G. van der Laan, Daresbury Laboratory (UK), lead to a much improved
understanding of the electronic structure of Gd and Tb and of magnetic
dichroism in photoemission in general.

\+ Combining strong magnetic circular dichroism in 4*f* photoemission
with layer dependent core-level shifts allowed characterizing the
magnetic properties of ultra-thin Eu films on Gd(0001) with atomic layer
resolution \[39, 40, 42, 45, 48\].

*Advisor*: Prof. Günter Kaindl

**Universität Regensburg, Regensburg, Germany** (1987-1992)

Diploma in Physics, with Honors

*Major research accomplishments*:

\+ Thin amorphous Fe films were prepared in sputtered Fe/Y multilayers
and characterized using SQUID, VSM, as well as Mössbauer spectroscopy.

\+ Up to (22±2)Å the Fe layers are amorphous and show spin-glass
behavior whereas thicker Fe layers crystallize in bcc structure and are
ferromagnetic.

*Advisor*: Prof. Dr. Günther Bayreuther

**[AWARDS, HONORS, AND FELLOWSHIPS]{.underline}**

**Klaus Halbach Award for Innovative Instrumentation at the ALS 2005\
"for the design and implementation of a versatile and highly popular
vector magnetometer for soft x ray studies"\
***(Given annually by the Advanced Light Source Users' Executive
Committee to a user or staff member at the Advanced Light Source for the
development of new and outstanding synchrotron radiation
instrumentation)*

**Lawrence Berkeley National Laboratory Outstanding Performance Award
2003\
***(Given for outstanding achievement in support of the missions and
goals of the Lawrence Berkeley National Laboratory)*

**Tim Renner User Services Award for Outstanding Support to the ALS User
Community 2001\
"for untiring efforts in supporting users at the elliptically polarizing
undulator beamline"***\
(Given annually by the Advanced Light Source Users' Executive Committee
to a staff member at the Advanced Light Source for outstanding support
of users)*

**Miller Research Fellowship Award 1997-1999\
***(Two-year postdoctoral research fellowship given annually to 8-10
science graduates by the Miller Institute for Basics Research in
Science, University of California, Berkeley, to conduct research at UC
Berkeley)*

**Ernst Eckhart Koch Award 1996\
***(given annually for the most outstanding doctoral thesis in the field
of research with synchrotron radiation performed either at the Berliner
Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung m. b. H.
(BESSY), Berlin, Germany or at Hamburger Synchrotronstrahlungslabor
(HASYLAB), Hamburg, Germany.)*

**[PEER REVIEWED PUBLICATIONS]{.underline}**

1.  **Elke Arenholz**, Kai Liu, Zhipan Li and Ivan K. Schuller\
    *Magnetization reversal of uncompensated Fe moments in exchange
    biased Ni/FeF~2~ bilayers*\
    Appl. Phys. Lett. **88**, 072503 (2006)

2.  K.W. Edmonds, G. van der Laan, A. Freeman, N.R.S. Farley, T.K.
    Johal, R.P. Campion, C.T. Foxon, B.L. Gallagher, and **E. Arenholz\
    ***Anisotropic x-ray magnetic circular dichroism from (Ga,Mn)As:
    identification of atomic-like and hybridized states\
    *Phys. Rev. Lett. **96**, 117207 (2006)

3.  H. Ohldag, H. Shi, **E. Arenholz**, J. Stöhr, and D. Lederman\
    *Parallel versus antiparallel interfacial coupling in
    exchange-biased Co/FeF~2~ bilayers\
    *Phys. Rev. Lett. **96,** 027203 (2006)

4.  A.A. Freeman, K.W. Edmonds, N.R.S. Farley, T.K. Johal, **E.
    Arenholz**, G. van der Laan, R.P. Campion, C.T. Foxon, B.L.
    Gallagher\
    *Anisotropic x-ray magnetic linear dichroism in (Ga,Mn)As\
    *Phys. Rev. B **73**, 233303 (2006)

5.  P. Sharma, H. Kimura, A. Inoue, **E. Arenholz**, and J.-H. Guo\
    *Temperature and thickness driven spin-reorientation transition in
    amorphous Co-Fe-Ta-B thin films\
    *Phys. Rev. B **73**, 052401 (2006)

6.  N.D. Telling, G. van der Laan, S. Ladak, R.J. Hicken, and **E.
    Arenholz\
    ***Evidence of a barrier oxidation dependence on the interfacial
    magnetism in Co/alumina based magnetic tunnel junctions\
    *J. Appl. Phys. **99**, 08E505 (2006)

7.  E. Negusse, J. Holroyd, M. Liberati, J. Dvorak, Y. U. Idzerda, T. S.
    Santos, J. S. Moodera, and **E. Arenholz**\
    *Effect of electrode and EuO thickness on EuO-electrode interface in
    tunneling spin-filter*\
    J. Appl. Phys. **99**, 08E507 (2006)

8.  D.A. Resnick, K. Gilmore, Y.U. Idzerda, M.T. Klem, M. Allen, T.
    Douglas, M. Young, and **E. Arenholz**\
    *Magnetic properties of Co~3~O~4~ nanoparticles mineralized in
    Listeria innocua Dps*\
    J. Appl. Phys. **99**, 08Q501 (2006)\
    This article has also been published in the virtual Journals\
    Virtual Journal of Biological Physics Research
    [http://www.vjbio.org](http://www.vjbio.org/).\
    Virtual Journal of Nanoscale Science & Technology
    <http://www.vjnano.org/>

9.  A. Ney, R. Rajarama, **E. Arenholz**, J. S. Harris, Jr., M.
    Samant, R. F. C. Farrow, and S. S. P. Parkin\
    *Structural and magnetic properties of Cr and Mn doped InN\
    *J. Magn. Magn. Mater. **300**, 7 (2006)

10. **Elke Arenholz**, and Kai Liu\
    *Angular dependence of the magnetization reversal in exchange biased
    Fe/MnF~2\
    ~*Appl. Phys. Lett. **87**, 132501 (2005)

11. **Elke Arenholz** and Soren O. Prestemon\
    *Design and performance of an eight pole resistive magnet for soft
    x-ray magnetic dichroism measurements\
    *Rev. Sci. Instrum. **76**, 083908 (2005)\
    This article has also been published in the virtual Journals
    [http://www.vjsuper.org](http://www.vjsuper.org/).

12. Justin Olamit, **Elke Arenholz**, Zhi-Pan Li, Oleg Petracic, Igor V.
    Roshchin, R. Morales, Xavier Batlle, Ivan K. Schuller, and Kai Liu\
    *Loop bifurcation and magnetization rotation in exchange-biased
    Ni/FeF~2\
    ~*Phys. Rev. B **72**, 012408 (2005)

13. N. Mannella, A. Rosenhahn, M. Watanabe, B. Sell, A. Nambu, S.
    Ritchey, **E. Arenholz**, A. Young, Y. Tomioka, and C.S. Fadley\
    *Temperature-dependent x-ray absorption spectroscopy of colossal
    magnetoresistive perovskites*\
    Phys. Rev. B **71**, 125117 (2005)

14. **E. Arenholz** and S.O. Prestemon\
    *Octupole magnet for soft x-ray magnetic dichroism experiments:
    design and performance*\
    AIP Conference Proc. **705**, 1170 (2004)

15. V. Perez-Dieste, J.N. Crain, A. Kirakosian, J.L. McChesney, **E.
    Arenholz**, A.T. Young, J.D. Denlinger, D.L. Ederer, T.A. Callcott,
    S.A. Lopez-Rivera, and F.J. Himpsel\
    *Unoccupied orbitals of 3d transition metals in ZnS\
    *Phys. Rev. B **70**, 085205 (2004)

16. F. Bartolome, J. Herrero-Albillos, L.M. Garcia, A.T. Young, T.
    Funk, N. Plugaru, and **E. Arenholz**\
    *Orbital moment at the Curie temperature in ErCo~2\
    ~*J. Magn. Magn. Mater. **272-276**, 319 (2004)

17. A. Scholl, M. Liberati, **E. Arenholz**, H. Ohldag, and J. Stöhr\
    *Creation of an antiferromagnetic exchange spring\
    *Phys. Rev. Lett. **92**, 247201 (2004)

18. T. Funk, P. Kennepohl, A. J. Di Bilio, W. A. Wehbi, A. T. Young, S.
    Friedrich, **E. Arenholz**, H. B. Gray, and S. P. Cramer\
    *X-ray Magnetic Circular Dichroism of Pseudomonas
    aeruginosaNickel(II) Azurin\
    *J. Am. Chem. Soc. **126**, 5859 (2004)

19. K.W. Edmonds, N.R.S. Farley, R.P. Campion, C.T. Foxon, B.L.
    Gallagher, T.K. Johal, G. van der Laan, M. MacKenzie, J.N. Chapman,
    and **E. Arenholz**\
    *Surface effects in Mn L~3,2~ x-ray absorption spectra from
    (Ga,Mn)As\
    *Appl. Phys. Lett. **84**, 4065 (2004)

20. T. Funk, S. Friedrich, A.T. Young, **E. Arenholz**, R. Delano, and
    S.P. Cramer\
    *Soft x-ray magnetic circular dichroism at 2 K: a tool in biological
    inorganic chemistry\
    *Rev. Sci. Instrum. **75**, 756 (2004)

21. M. Taguchi, G. van der Laan, **E. Arenholz**, S.S. Dhesi, and E.
    Dudzik\
    *Magnetic circular dichroism and spin polarization in 3d to 4f
    resonant photoemission from Tb metal in the perpendicular geometry\
    *Phys. Rev. B **68**, 104408 (2003)

22. H. Ohldag, A. Scholl, F. Nolting, **E. Arenholz**, S. Maat S, A.T.
    Young, M. Carey, and J. Stöhr\
    *Correlation between exchange bias and pinned interfacial spins\
    *Phys. Rev. Lett. **91**, 017203 (2003)

23. Th. Weber, M. Weckenbrock, M. Balser, L. Schmidt, O. Jagutzki, W.
    Arnold, O. Hohn, M. Schöffler, **E. Arenholz**, T. Young, T.
    Osipov, L. Foucar, A. D. Fanis, R.D. Muino, H. Schmidt-Böcking, C.L.
    Cocke, M.H. Prior, and R. Dörner\
    *Auger electron emission from fixed-in-space CO\
    *Phys. Rev. Lett. **90**, 153003 (2003)

24. A.T. Young, **E. Arenholz**, F. Jun, H. Padmore, S. Marks, R.
    Schlueter, E. Hoyer, N. Kelez, and C. Steier\
    *A soft x-ray undulator beamline at the Advanced Light Source with
    circular and variable linear polarization for the spectroscopy and
    microscopy of magnetic materials\
    *Surf. Rev. Lett. **9**, 549 (2002)

25. A.T. Young, **E. Arenholz**, S. Marks, R. Schlueter, C. Steier, H.A.
    Padmore, A.P. Hitchcock, and D.G. Castner\
    *Variable linear polarization from an X-ray undulator\
    *J. Synchrotron Rad. **9**, 270 (2002)

26. S. Yang, B.S. Mun, N. Mannella, S. Kim, J.B. Kortright, J.
    Underwood, F. Salmassi, **E. Arenholz**, A. Young, Z. Hussain, M.A.
    Van Hove, and C.S. Fadley\
    P*robing buried interfaces with soft x-ray standing wave
    spectroscopy: application to the Fe/Cr interface*\
    J. Phys. C: Solid State Phys. **14**, L407-20 (2002)

27. T. Jahnke, Th. Weber, A. Landers, A. Knapp, S. Schossler, J.
    Nickles, S. Kammer, O. Jagutzki, L. Schmidt, A. Czasch, T. Osipov,
    **E. Arenholz**, A.T. Young, R.D. Muino, D. Rolles, F.J.G. de Abajo,
    C.S. Fadley, M.A. Van Hove, S.K. Semenov, N.A. Cherepkov, J. Rosch,
    M.H. Prior, H. Schmidt-Böcking, C.L. Cocke, and R. Dörner\
    *Circular dichroism in K-shell ionization from fixed-in-space CO and
    N~2~ molecules\
    *Phys. Rev. Lett. **88**, 073002 (2002)

28. T. Funk, S. Friedrich, A. Young, **E. Arenholz**, and S.P Cramer\
    *Requirements for x-ray magnetic circular dichroism on paramagnetic
    biological systems and model compounds*\
    Rev. Sci. Instrum. **73**, 1649 (2002)

29. A.T. Young, J. Feng, **E. Arenholz**, H.A. Padmore, T. Henderson, S.
    Marks, E. Hoyer, R. Schlueter, J.B. Kortright, V. Martynov, C.
    Steier, and G. Portmann\
    *First commissioning results for the elliptically polarizing
    undulator beamline at the Advanced Light Source\
    *Nucl. Instr. and Meth. A **467-468**, 549 (2001)

30. A.W. Kay, F.J. Garcia de Abajo, S. Yang, **E. Arenholz**, B.S.
    Mun, N. Mannella, Z. Hussain, M.A. Van Hove, and C.S. Fadley\
    *Multi-atom resonant photoemission*\
    J. Electron Spectrosc. Relat. Phenom. **114-116**, 1179 (2001)

31. A.W. Kay, F.J.G. de Abajo, S. Yang, **E. Arenholz**, B.S. Mun, N.
    Mannella, Z. Hussain, M. Van Hove, and C.S. Fadley\
    *Multiatom resonant photoemission\
    *Phys. Rev. B **63**, 115119 (2001)

32. C.S. Fadley, **E. Arenholz**, A.W. Kay, J.G. de Abajo, B.S. Mun, S.
    Yang, Z. Hussain, and M. Van Hove\
    *Multi-atom resonant photoemission\
    *AIP Conference Proc. **506**, 251 (2000)

33. **E. Arenholz**, A.W. Kay,C.S. Fadley, M. Grush, T.A.
    Callcott, D. L. Ederer, C. Heske, and Z. Hussain\
    *Multi-atom resonant photoemission observed via secondary processes:
    Auger decay and x-ray fluorescence\
    *Phys. Rev. B **61**, 7183 (2000)

34. K. Starke, **E. Arenholz**, and G. Kaindl\
    *Magnetic dichroism in photoemission: a new element-specific
    magnetometer with atomic-layer resolution\
    *Mater. Sci. Forum. **315-317**, 113 (1999)

35. A.W. Kay, **E. Arenholz**, B.S. Mun, J. Garcia de Abajo, C.S.
    Fadley, R. Denecke, Z. Hussain, and M.A. Van Hove\
    *Multiple atom resonant photoemission: a new technique for studying
    near-neighbor atomic identities and bonding*\
    J. Electron Spectrosc. Relat. Phenom. **101-103**, 647 (1999)

36. R.K. Kawakami, E. Rotenberg, H.J. Choi, E. Escorcia-Aparicio, M.O.
    Bowen, J.H. Wolfe, **E. Arenholz**, Z.D. Zhang, N.V. Smith, and Z.Q.
    Qiu\
    *Quantum-well states in copper thin films\
    *Nature **398**, 132 (1999)

37. Z. Hu, K. Starke, G. van der Laan, E. Navas, A. Bauer, E.
    Weschke, C. Schüssler-Langeheine, **E. Arenholz**, A. Mühlig, G.
    Kaindl, J.B. Goodkoep, and N.B. Brookes\
    *Spin flip in resonant photoemission from Gd\
    *Phys. Rev. B **59**, 9737 (1999).

38. G. van der Laan, **E. Arenholz**, Z. Hu, A. Bauer, E. Weschke, C.
    Schüssler-Langeheine, E. Navas, A. Mühlig, G. Kaindl, J.B. Geodkoop,
    and N.B. Brookes\
    *Magnetic circular dichroism in Tb 3d to 4f resonant photoemission\
    *Phys. Rev. B **59**, 8835 (1999)

39. **E. Arenholz**, K. Starke, G. Kaindl, and P.J. Jensen\
    *Interfacial magnetism of Eu/Gd(0001) studied by magnetic circular
    dichroism in photoemission\
    *Phys. Rev. Lett. **80**, 2221 (1998)

40. **E. Arenholz**, K. Starke, and G. Kaindl\
    *Magnetic properties of thin Eu films on Gd(0001) studied by
    magnetic circular dichroism in photoemission\
    *Mater. Res. Soc. Symp. Proc. **475,** 487 (1997)

41. K. Starke, G. van der Laan, Z. Hu, **E. Arenholz**, E. Navas, A.
    Bauer, A. Mühlig, C.S. Langeheine, E. Weschke, J. Goodkoep, N.
    Brookes, and G. Kaindl\
    *Magnetic dichroism in resonant photoemission and photoabsorption
    from Gd metal\
    *Mater. Res. Soc. Symp. Proc. **475**, 371 (1997)

42. **E. Arenholz**, K. Starke, and G. Kaindl\
    *Layer-dependent magnetization in ultrathin Eu films on Gd(0001)\
    *Appl. Phys. Lett. **71**, 3430 (1997)

43. G. van der Laan, **E. Arenholz**, E. Navas, Z. Hu, E. Mentz, A.
    Bauer, and G. Kaindl\
    *Magnetic circular dichroism in 5p photoemission from Gd and Tb
    metal*\
    Phys. Rev. B **56**, 3244 (1997)

44. K. Starke, E. Navas, **E. Arenholz**, Z. Hu, L. Baumgarten, G. van
    der Laan, C.T. Chen, and G. Kaindl\
    *Magnetic circular dichroism in 4d to 4f resonant photoemission and
    photoabsorption of Gd metal\
    *Phys. Rev. B **55**, 2672 (1997)

45. **E. Arenholz**, K. Starke, E. Navas, and G. Kaindl\
    *Application of MCD in 4f photoemission as an element-specific probe
    for near-surface magnetization in lanthanide materials\
    *J. Electron Spectrosc. Relat. Phenom. **78**, 241 (1996)

46. G. van der Laan, **E. Arenholz**, E. Navas, A. Bauer, and G. Kaindl\
    *Magnetic circular dichroism and orbital momentum coupling in 4d
    photoemission from Gd(0001)\
    *Phys. Rev. B **53**, R5998 (1996)

47. K. Starke, E. Navas, **E. Arenholz**, and G. Kaindl\
    *Magnetic circular dichroism in photoemission from lanthanide
    materials\
    *in *Spin-Orbit-Influenced Spectroscopies of Magnetic Solids* edited
    by H. Ebert and G. Schütz (Lecture Notes in Physics, Springer
    Verlag, Berlin, Germany, 1996), pp. 65-84

48. **E. Arenholz**, K. Starke, and G. Kaindl\
    *Interfacial magnetism studied by MCD in 4f photoemission:
    Eu/Gd(0001)\
    *J. Electron Spectrosc. Relat. Phenom. **76**, 183 (1995)

49. K. Starke, E. Navas, **E. Arenholz**, L. Baumgarten, and G. Kaindl\
    *Magnetic circular dichroism in photoemission from rare earth
    materials: a new technique in surface and thin-film magnetism\
    *IEEE Trans. Mag. **31**, 3313 (1995)

50. **E. Arenholz**, E. Navas, K. Starke, L. Baumgarten, and G. Kaindl\
    *Magnetic circular dichroism in core-level photoemission from Gd,
    Tb, and Dy in ferromagnetic materials\
    *Phys. Rev. B **51**, 8211 (1995)

51. K. Starke, E. Navas, **E. Arenholz**, L. Baumgarten, and G. Kaindl\
    *Circular dichroism in 4f photoemission from magnetically ordered
    rare-earth materials\
    *Appl. Phys. A **60**, 179 (1995)

52. G. Kaindl, E. Navas, **E. Arenholz**, L. Baumgarten, and K. Starke\
    *Magnetic circular dichroism in photoemission from rare earth
    materials: basic concepts and applications\
    *in *Core-Level Spectroscopy for Magnetic Phenomena: Theory and
    Experiments*, edited by P.S. Bagus, G. Pacchioni, and F. Parmigiani
    (NATO ASI Series B, Plenum, New York, USA, 1995), pp. 131-151

53. A.V. Fedorov, **E. Arenholz**, K. Starke, E. Navas, L.
    Baumgarten, C. Laubschat, and G. Kaindl\
    *Surface shifts of 4f electron-addition and electron-removal states
    in Gd(0001)\
    *Phys. Rev. Lett. **73**, 601 (1994)

54. K. Starke, L. Baumgarten, **E. Arenholz**, E. Navas, and G. Kaindl\
    M*agnetic circular dichroism in 4f photoemission from terbium\
    *Phys. Rev. B **50**, 1317 (1994)