176
5 Compositionally Modulated and Multilayered Deposits
additives) into the Cr-rich layer, which is likely to have influenced the mechanical
properties, too.
Finally, the Fe/Pt system must be mentioned where annealing can be indispensable for the post-treatment of electrodeposited multilayers. The importance of the
annealing in the Fe–Pt system stems from that the desired L1 0 structure of the
FePt alloys with nearly equimolar composition does not form at room-temperature
deposition. Additionally, the oxygen incorporation during the electroplating process
prevents the achievement of the desired magnetic properties when the equimolar
alloy is deposited. For the preparation of the layer with desired composition, a very
elegant solution was suggested with a multilayer approach [188]. Namely, a multilayer structure is deposited first with Fe-rich and Pt-rich layers, both of them with
relatively small oxygen impurity as compared to the direct plating of FePt deposits.
Then, the resulting multilayer can be annealed at a temperature where the homogenization of the multilayer takes place. Hence, the indispensable heat treatment for
obtaining the desired phase structure was coupled with the sample homogenization,
and the drawback of the oxygen impurity could be avoided by plating a metal-rich
multilayer system as a starting material for annealing. The heat treatment accompanied with partial recrystallization was also essential for achieving a high-coercivity
coating from a multilayer composed of Fe 75 Pt 25 and Fe 50 Pt 50 sublayers [189]. Interestingly, the samples with 15 nm layer thicknesses did not homogenize even at 650
o C
annealing temperature but develop a mixed bcc/fcc crystalline system where the coercivity of the individual layers could be identified from magnetization measurement.
Extremely high coercivity of 12 kOe was achieved with the combined multilayer
electroplating–annealing approach.
References
1. Ross CA (1994) Annu Rev Mater Sci 24:159–187
2. Leisner P, Nielsen CB, Tang PT, Dörge TC, Møller P (1996) J Mater Proc Technol 58:39–44
3. Wilcox GD (2004) J Corros Sci Eng 6: Paper 52
4. Roy S (2009) Electrochemical fabrication of nanostructured, compositionally modulated
metal multilayers (CMMMs). In: Schmuki P (ed) Electrochemistry at the nanoscale. Springer,
New York, pp 349–376
5. Bakonyi I, Hansal WEG (2018) Trans IMF 96:237–243
6. Bakonyi I, Péter L (2010) Progr Mater Sci 55:107–245
7. Blum W (1921) Trans Am Electrochem Soc 40:307–320
8. NabiRahniy DMA, Tang PT, Leisner P (1996) Nanotechnology 7:134–143
9. El Bahraoui T, Errahmani H, Berrada A, Dinia A, Schmerber G, Cherkaoui El Mourslic F,
Hajji F, Lassri H (2004) J Magn Magn Mater 272–276:e955–e957
10. El Bahraoui T, Errahmani H, Belghazi Y, Berrada A, Dinia A, Schmerber G, Lassri H,
Cherkaoui El Moursli F, Hajji F (2007) J Magn Magnc Mater 316:8–12
11. Lghazi Y, Moubah R, Bimaghra I, Hlil EK, El Bahraoui T, Alleg S, Lassri H (2017) J Supercond
Nov Magn 30:2641–2645
12. Haseeb ASMA, Celis JP, Roos JR (1994) J Electrochem Soc 141:230–237
13. Lamovec J, Jovi´ c V, Vorkapi´ c M, Popovi´ c B, Radojevi´ c V, Aleksi´ c R (2011) J Min Metall
Sect B-Metall 47:53–61
5 Compositionally Modulated and Multilayered Deposits
additives) into the Cr-rich layer, which is likely to have influenced the mechanical
properties, too.
Finally, the Fe/Pt system must be mentioned where annealing can be indispensable for the post-treatment of electrodeposited multilayers. The importance of the
annealing in the Fe–Pt system stems from that the desired L1 0 structure of the
FePt alloys with nearly equimolar composition does not form at room-temperature
deposition. Additionally, the oxygen incorporation during the electroplating process
prevents the achievement of the desired magnetic properties when the equimolar
alloy is deposited. For the preparation of the layer with desired composition, a very
elegant solution was suggested with a multilayer approach [188]. Namely, a multilayer structure is deposited first with Fe-rich and Pt-rich layers, both of them with
relatively small oxygen impurity as compared to the direct plating of FePt deposits.
Then, the resulting multilayer can be annealed at a temperature where the homogenization of the multilayer takes place. Hence, the indispensable heat treatment for
obtaining the desired phase structure was coupled with the sample homogenization,
and the drawback of the oxygen impurity could be avoided by plating a metal-rich
multilayer system as a starting material for annealing. The heat treatment accompanied with partial recrystallization was also essential for achieving a high-coercivity
coating from a multilayer composed of Fe 75 Pt 25 and Fe 50 Pt 50 sublayers [189]. Interestingly, the samples with 15 nm layer thicknesses did not homogenize even at 650
o C
annealing temperature but develop a mixed bcc/fcc crystalline system where the coercivity of the individual layers could be identified from magnetization measurement.
Extremely high coercivity of 12 kOe was achieved with the combined multilayer
electroplating–annealing approach.
References
1. Ross CA (1994) Annu Rev Mater Sci 24:159–187
2. Leisner P, Nielsen CB, Tang PT, Dörge TC, Møller P (1996) J Mater Proc Technol 58:39–44
3. Wilcox GD (2004) J Corros Sci Eng 6: Paper 52
4. Roy S (2009) Electrochemical fabrication of nanostructured, compositionally modulated
metal multilayers (CMMMs). In: Schmuki P (ed) Electrochemistry at the nanoscale. Springer,
New York, pp 349–376
5. Bakonyi I, Hansal WEG (2018) Trans IMF 96:237–243
6. Bakonyi I, Péter L (2010) Progr Mater Sci 55:107–245
7. Blum W (1921) Trans Am Electrochem Soc 40:307–320
8. NabiRahniy DMA, Tang PT, Leisner P (1996) Nanotechnology 7:134–143
9. El Bahraoui T, Errahmani H, Berrada A, Dinia A, Schmerber G, Cherkaoui El Mourslic F,
Hajji F, Lassri H (2004) J Magn Magn Mater 272–276:e955–e957
10. El Bahraoui T, Errahmani H, Belghazi Y, Berrada A, Dinia A, Schmerber G, Lassri H,
Cherkaoui El Moursli F, Hajji F (2007) J Magn Magnc Mater 316:8–12
11. Lghazi Y, Moubah R, Bimaghra I, Hlil EK, El Bahraoui T, Alleg S, Lassri H (2017) J Supercond
Nov Magn 30:2641–2645
12. Haseeb ASMA, Celis JP, Roos JR (1994) J Electrochem Soc 141:230–237
13. Lamovec J, Jovi´ c V, Vorkapi´ c M, Popovi´ c B, Radojevi´ c V, Aleksi´ c R (2011) J Min Metall
Sect B-Metall 47:53–61