Modulation of magnetic and structural properties of cobalt thin films by means of electrodeposition

Abstract

Cobalt electrodeposits were prepared from an electrolytic bath containing cobalt perchlorate. The effect of different species, organic (thiourea and sodium gluconate) and inorganic (boric acid), on the crystallographic structure, morphology, magnetic properties and electrochemical behaviour of cobalt electrodeposits was investigated. Amorphous cobalt, hcp cobalt and a non-usual primitive cubic cobalt phase were observed depending on the bath composition. Depending on the structure, different morphologies and magnetic properties were found. Coercivity values of the cobalt coatings ranged from around 15 Oe for amorphous, nodular deposits to 380 Oe for cobalt coatings showing acicular morphology and hcp structure with a (002) preferred orientation. Knowledge of the influence of the species on the properties of cobalt makes it possible to obtain tailored cobalt films. © 2008 Springer Science+Business Media B.V

In Situ Stress Measurements during Cobalt Electrodeposition on (111)-Textured Au

“…This has several ramifications. The first being the possible precipitation of Co(OH) 2 Given the fact that the tensile stress seems to track the decrease in the faradaic efficiency for Co deposition, the obvious next step is to examine the role of hydrogen. Similar to many of the Fe-group metals, the cobalt -hydrogen phase diagram exhibits some very interesting behavior.…”

“…[4][5][6][7][8][9][10][11] These properties are largely dependent upon the structure and morphology of the electrodeposit, which in the case of cobalt can vary dramatically with overpotential, electrolyte pH, and the presence of strongly adsorbing anions. 2,[12][13][14][15][16] …”

“…The use of electrodeposited Co-based materials has attracted much attention over the past several decades owing in part to their interesting magnetic [1][2][3] and catalytic properties. [4][5][6][7][8][9][10][11] These properties are largely dependent upon the structure and morphology of the electrodeposit, which in the case of cobalt can vary dramatically with overpotential, electrolyte pH, and the presence of strongly adsorbing anions.…”

“…[4][5][6][7][8][9][10][11] These properties are largely dependent upon the structure and morphology of the electrodeposit, which in the case of cobalt can vary dramatically with overpotential, electrolyte pH, and the presence of strongly adsorbing anions. 2,[12][13][14][15][16] For example, solutions with a pH < 2.5 will generally result in a mixture of both face-centered cubic (fcc) and hexagonal close-packed (hcp) Co on Au, 13,17 while more alkaline solutions yield nearly pure hcp Co. 3,12,[17][18][19] The magnetic properties of Co are particularly structure sensitive. Ultrathin (< 2 nm) Co, electrodeposited onto Au (111), exhibits perpendicular magnetic anisotropy and highly square hysteresis loops, identical to that of vacuum deposited Co/Au films.…”

Magnetic Field Effects on Surface Morphology and Magnetic Properties of Co–Ni–N Thin Films Prepared by Electrodeposition

“…The need to understand the effect of an applied magnetic field (MF) on ferromagnetic particles (e.g., Co, Ni, Fe) in electrochemical deposition on the microstructure, morphology, and magnetic properties of the electrodeposited material enhanced research in this domain in the last years [1][2][3][4][5].…”