Transcript Slajd 1

Spin reorientation in the Er2-xFe14+2xSi3
single-crystal studied by Mössbauer spectroscopy
J. Żukrowski 1, A. Błachowski 2, K. Ruebenbauer 2, J. Przewoźnik 1,
D. Sitko 3, N.-T.H. Kim-Ngan 3, Z. Tarnawski 1, A.V. Andreev 4
1
Solid State Physics Department,
Faculty of Physics and Applied Computer Science,
AGH University of Science and Technology, Kraków, Poland
2
Mössbauer Spectroscopy Division, Institute of Physics,
Pedagogical University, Kraków, Poland
3
Surface Physics Division, Institute of Physics,
Pedagogical University, Kraków, Poland
4
Institute of Physics,
Academy of Sciences, Prague, Czech Republic
Er2-xFe14+2xSi3 single-crystal
Bulk magnetic moment versus temperature
in the moderate external field 0.1 T aligned along the c-axis
Magnetic susceptibility versus temperature for various AC frequencies in the null external field
and for the moderate external field 0.1 T applied along the c-axis.
The AC field was applied along the c-axis.
Er2-xFe14+2xSi3
1
2
111
 g11
 

2
 0  0
2
111

1

cos
(

)
2
g
1
111
0
11

g11 
and  0  acos 
2
111

2sin (  0 )
2
g

1
11


K. Ruebenbauer, Physica B 172, 346 (1991)


Er2-xFe14+2xSi3 powder sample
Site
c (%)
T (K)
±1
111
g11
4f
14
6g
B (T)
S (mm/s)
Δ (mm/s)
B (T)
Error
300
80
4.2
±0.01
0.94
1.00
0.98
±0.1
24.3
32.0
31.7
±0.01
0.12
0.26
0.26
±0.01
0.05
-0.11
-0.08
±0.1
±0.01
17.4
15.2
0.01
21.8
19.7
0.12
22.2
20.4
0.14
±0.01
±0.03
±0.1
±0.2
±0.01
0.13
0.27
21.4
19.9
-0.02
-0.06
0.02
26.2
25.2
0.03
-0.03
0.11
26.6
26.6
0.07
±0.01
±0.04
±0.1
±0.01
-0.07
-0.22
19.5
18.4
-0.04
-0.38
0.11
24.4
25.5
0.11
-0.05
-0.55
24.7
24.5
0.11
±0.01
±0.04
±0.2
0.13
0.17
6.5
-0.30
0.27
7.6
-0.17
0.12
8.1
±0.03
0.22
0.66
0.56
±0.1
0.3
0.6
0.6
21
S (mm/s)
Δ (mm/s)
12j or 12k B (T)
30
S (mm/s)
Δ (mm/s)
12k or 12j B (T)
32
S (mm/s)
Δ (mm/s)
2b  4e
3
B (T)
S (mm/s)
Δ (mm/s)

Er2-xFe14+2xSi3 single-crystal
Average angle between c-axis
and
iron hyperfine fields
0.5



Contribution from iron atoms
with hyperfine field perpendicular to c-axis
Contribution (at. % Fe)
4f
6g
12j or 12k
12k or 12j
2b > 4e

Er2-xFe14+2xSi3
Conclusions
Spin reorientation from the [a - b] plane onto the c-axis
occurs for all iron sub-lattices except for iron dumbbells substituting erbium (2b)
in the temperature range 130 – 80 K due to the domain flip mechanism.
Spin reorientation is less perfect for the sub-lattices (12j) and (12k) containing silicon.
Gradual second spin reorientation occurs below 50 K
leading to the partial recovery of the high temperature spin structure.