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Magnetism of Eu and Dy under Extreme Pressures
Wenli Bi
Advanced Photon Source, Argonne National Laboratory, Argonne COMPRES (University of Illinois at Urbana-Champaign)
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2
High pressure SMS experiment setup
Ruby%system%
21#Magnetism of Eu and Dy under Extreme Pressures Wenli Bi Advanced - - PowerPoint PPT Presentation
Magnetism of Eu and Dy under Extreme Pressures Wenli Bi Advanced - - PowerPoint PPT Presentation
Magnetism of Eu and Dy under Extreme Pressures Wenli Bi Advanced Photon Source, Argonne National Laboratory, Argonne COMPRES (University of Illinois at Urbana-Champaign) 1 High pressure SMS experiment setup Ruby%system% 21# 2 Basic
SLIDE 2
SLIDE 3
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Basic Mössbauer parameters of 151Eu
- R. Röhlsberger, Nuclear Condensed Ma/er Physics with Synchrotron Radia8on, (Springer Berlin Heidelberg, Berlin, Heidelberg, 2005), Ch. 2, p. 25.
151
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4
quadrupole interaction in Eu magnetic interaction in Eu
Hyperfine interactions of 151Eu
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5
Simulations of Mӧssbauer spectra of Eu
Energy domain Time domain
Simulated Mössbauer data in 151Eu
SLIDE 6
Experimental lab Mössbauer data in 151Eu
Cohen et. al., Phys. Rev. 184, 263 (1969). Barrett and D. Shirley, Phys. Rev. 131, 123 (1963). Shaken et al., Phys. Rev. Lett. 55, 312 (1985). Malik et al.,Phys. Rev. Lett. 55, 316 (1985).
QS = 33 mm/s H = 26.5 T
SLIDE 7
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Eu2+: (4f7, J=7/2) Eu3+: (4f6, J=0)
Data taken from Mössbauer effect data center, http://www.medc.dicp.ac.cn/
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8 Courtesy of E. E. Alp
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Bi et al., Phys. Rev. B. 93, 184424 (2016).
magnetic sc
Pressure induced magnetic transition in Eu (4f75d06s2 J = 7/2)
10 10
2
10 10
2
10
4
10 10
2
10
4
10
2
10
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counts
10 10
2
10
4
10 10
2
10
4
10 10
2
10 10
2
20 40 60 80
time (ns)
10 10
2
- 60 -40 -20
20 40 60
velocity (mm/s) 8 GPa 12.3 GPa 17.5 GPa 47 GPa 59 GPa 67 GPa 81 GPa 93 GPa 101 GPa
SLIDE 10
Röhler, Phys. B+C 144, 27 (1986). Bi et al., Phys. Rev. B. 93, 184424 (2016).
No significant valence change in Eu
experiment data ab-initial
SLIDE 11
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Basic Mössbauer parameters of 161Dy (4f95d16s2, J = 15/2)
- R. Röhlsberger, Nuclear Condensed Ma/er Physics with Synchrotron Radia8on, (Springer Berlin Heidelberg, Berlin, Heidelberg, 2005), Ch. 2, p. 25.
151
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Lim et al., Phys. Rev. B 91, 045116 (2015). Samudrala et al., High Press. Res. 34, 266 (2014).
Doniach model
TRKKY ~ J 2 Tk ~ exp(⎮J⎮)
Magnetism in Dy
SLIDE 13
40 cm/s spliMng (0.12 ns), beyond the APD Qme resoluQon (1 ns). As a result, only the inner spliMng can be resolved from Qme domain spectrum.
13
77"K"
G.J."Bowden,"D.S.P."Bunbury,"and"J.M."Williams,"Proc."Phys."Soc."91,"612"(1967)."
~"0.1"ns" ~"0.4"ns" ~"5"ns" velocity (cm/s)
Hhf = 550 T
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20 40 60 80 100 120 time (ns) counts 0.01 ns 0.1 ns 1 ns
Dy SMS simulation with different detector time resolution Hhf = 574 T
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- Y. V Shvyd’ko et al., Europhys. LeX. 56, 309 (2001).
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Magnetic hyperfine field in Eu (6s24f75d0)
hf C CE n
H H H H = + +
C
H
CE
H
n
H
at#4.2#K#
HC:$insensi,ve#to#volume#change.# HCE$and#Hn:$dependent#of#volume#(pressure)# #change.#RKKY#interac,on.# $
Elmegid$and$Kaindl,$hyperfine$interac7ons$4,$420$(1978).$ Klein,$Wortmann$and$Kalvius,$18,291$(1976);$$ Nowik,$Dunlap$and$Wernick,$Phys.$Rev.$B$8,$238$(1973).$ Hüfner$and$Wernick,$Phys.$Rev.$173,$448$(1968)$ $