Correlations between morphology, crystal structure, and magnetization of epitaxial cobalt-platinum films grown with pulsed laser ablation

Rakshit, R. K.; Bose, Supratik; Sharma, Rohit; Budhani, R. C.; Vijaykumar, T. N.; Neena, S. J.

doi:10.1063/1.2832763

Cited by 23 publications

(15 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A major part of the research being conducted in the Condensed Matter -Low Dimensional Systems Laboratory of the Physics Department at IIT Kanpur is geared towards these objectives Rakshit et al , 2008. Both liquid and vapour phase synthesis routes are being used to prepare colloidal solution of nanoparticles, quantum dot structures supported on substrates and ultra thin (~ 10 nm) single crystal films.…”

Section: Introductionmentioning

confidence: 99%

“…Magnetic materials in zero, one and two-dimensional geometries such as clusters consisting of a few thousand atoms (Sun et al 2000;, wires with nanometer scale diameter (Tatara and Fakuyama 1997;Hong and Giordano 1998) and ultra thin films, respectively (Shima et al 2004;Rakshit et al , 2008, have been at the centre stage of condensed matter/ materials physics, and are the basis of a myriad of technologies. The fundamental interest in low dimensional magnetic materials emanates from the fact that a macroscopic property such as magnetization, which is a consequence of the cooperative response of millions of spins, can be altered in a non-trivial manner if a large fraction of these spins are made to reside on the surfaces or interfaces of a magnetic entity (Kodama 1999).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nanomagnetics with lasers

Budhani

Rakshit

2008

Bull Mater Sci

Self Cite

View full text Add to dashboard Cite

Both liquid and vapour phase pulsed laser deposition (PLD) techniques have been used to synthesize nanophase magnetic alloys of CoPt. While the liquid route results in soft phase (disordered fcc) nanoparticles of CoPt near equiatomic composition dispersed in a surfactant-polymer matrix, the conventional vapour phase PLD allows growth of high coercivity nanoscale structures of CoPt on (001) SrTiO 3 . The magnetization, M(T ), dynamics of the colloidal particles is examined. Two distinct particle distributions are established from analysis of M(T ) data, in conformity with results of electron microscopy. In vapour deposited films at low growth rate (~ 0⋅4 Å/s), morphology changes from a self-similar fractal to nanodots as the deposition temperature is raised from 700-800°C. The large lattice mismatch between (001) SrTiO 3 and the ac/bc plane of L1 0 ordered phase imparts tensile strain to the films whose morphological manifestations can be suppressed at high growth rates.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nanomagnetics with lasers

Budhani

Rakshit

2008

Bull Mater Sci

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the present paper, the notations of plane and direction based on face-centered cubic (fcc) structure In order to investigate the mechanism of thin film growth, it is useful to employ an epitaxial film, since the crystallographic orientation can be controlled by that of single-crystal substrate. FePt , CoPt [61][62][63][64][65][66][67][68][69][70][71][72][73] , and FePd [58][59][60][64][65][66][67][74][75][76][77][78][79] epitaxial films have been prepared on (001) substrates of MgO, SrTiO3, etc. The c-axis orientation has been investigated by high-resolution transmission electron microscopy 30,48) , selected area electron diffraction 49) , in-plane 19,[64][65][66][67] and pole-figure 50) X-ray diffractions (XRDs), and reflection high-energy electron diffraction (RHEED) [64][65][66][67] .…”

Section: Introductionmentioning

confidence: 99%

Alignment of c-Axis Orientation Perpendicular to the Substrate Surface in FePt Alloy Thin Film with L10 Structure

et al. 2015

View full text Add to dashboard Cite

An FePt alloy thin film with L10 structure formed on a (001)-oriented polycrystalline underlayer or on a (001)-oriented single-crystal substrate may involve (100) variant with the c-axis lying in the film plane in addition to (001) variant with the c-axis normal to the substrate surface. In the present study, FePt(2-40 nm) films with and without MgO(2 nm) cap layers are prepared on MgO(001) single-crystal substrates by employing a two-step formation method consisting of low-temperature deposition followed by high-temperature annealing. Disordered FePt(001) single-crystal films with and without MgO(001) single-crystal cap layers epitaxially grow on the substrates at 200 °C. For the films thinner than 10 nm, the in-plane and out-of-plane lattices are respectively expanded and shrunk due to accommodation of the lattice misfit of film with respect to the substrate. With increasing the thickness up to 40 nm, the strain is relaxed. The phase transformation from A1 to L10 occurs when the films are annealed at 600 °C. The cap layer seems to prevent the strain release and to promote the phase transformation along the perpendicular direction. The c-axis orientation is controlled to be perpendicular by using the two-step method for the FePt films of thicknesses less than 10 nm with MgO cap layers. On the contrary, the film of 40 nm thickness with cap layer and the films of 2-40 nm thicknesses without cap layers involve small volumes of L10(100) variant. The order degrees of films with cap layers are higher than those of films without cap layers. The films with cap layers have flat surfaces with the arithmetical mean roughness values lower than 0.3 nm for all the investigated thicknesses, whereas an island-like surface is formed for the 2-nm-thick film without cap layer. The film consisting of only L10(001) variant shows a strong perpendicular magnetic anisotropy and a very low in-plane coercivity. Introduction of MgO cap layer is useful in aligning the c-axis perpendicular to the substrate surface, enhancing the L10 ordering, forming a flat surface, and achieving a strong perpendicular magnetic anisotropy.

show abstract

“…The morphology and the magnetic properties were investigated for different crystal size. 6 Recently, some progresses have been achieved in the elaboration of these alloy NCs, using pulsed laser depositions 7,8 or thermal decomposition methods, 9,10 with even the observation of a partial in situ transformation of NCs toward the L1 0 phase without the need of post-stage annealing. We showed that the use of HOPG substrate both limits the coalescence effects and promotes the structural ordering.…”

mentioning

confidence: 99%