Large-area patterning of sub-100 nm epitaxial L1 FePt dots array via nanoimprint lithography

Li, Zheng; Zhang, Wei; Krishnan, Kannan M.

doi:10.1063/1.4929578

Cited by 6 publications

(4 citation statements)

References 42 publications

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“…The hexagonal array of FePt nanoparticles reveals a large coercivity of 1.5 T, much larger than the nanoparticles fabricated by top-down approaches. [51][52][53][54][55] Most of the top-down methods use either e-beam lithography, 53,55 nanoimprinting 52 or the self-assembled co-polymer 51,54 to define the pattern size of masks. All of them need to use ion etching for pattern transferring, and the ion damage usually causes the reduction of coercivity due to the disordering of the FePt L1 0 structure as the high coercivity of FePt is believed to originate from the L1 0 atomic ordering structure.…”

Section: Magnetic Propertiesmentioning

confidence: 99%

Thermal dewetting with a chemically heterogeneous nano-template for self-assembled L1₀FePt nanoparticle arrays

et al. 2016

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A design for the fabrication of metallic nanoparticles is presented by thermal dewetting with a chemically heterogeneous nano-template. For the template, we fabricate a nanostructured polystyrene-b-polydimethylsiloxane (PS-b-PDMS) film on a Si|SiO2 substrate, followed by a thermal annealing and reactive ion etching (RIE) process. This gives a template composed of an ordered hexagonal array of SiOC hemispheres emerging in the polystyrene matrix. After the deposition of a FePt film on this template, we utilize the rapid thermal annealing (RTA) process, which provides in-plane stress, to achieve thermal dewetting and structural ordering of FePt simultaneously. Since the template is composed of different composition surfaces with periodically varied morphologies, it offers more tuning knobs to manipulate the nanostructures. We show that both the decrease in the area of the PS matrix and the increase in the strain energy relaxation transfer the dewetted pattern from the randomly distributed nanoparticles into a hexagonal periodic array of L10 FePt nanoparticles. Transmission electron microscopy with the in situ heating stage reveals the evolution of the dewetting process, and confirms that the positions of nanoparticles are aligned with those of the SiOC hemispheres. The nanoparticles formed by this template-dewetting show an average diameter and center-to-center distance of 19.30 ± 2.09 nm and 39.85 ± 4.80 nm, respectively. The hexagonal array of FePt nanoparticles reveals a large coercivity of 1.5 T, much larger than the nanoparticles fabricated by top-down approaches. This approach offers an efficient pathway toward self-assembled nanostructures in a wide range of material systems.

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Section: Magnetic Propertiesmentioning

confidence: 99%

Thermal dewetting with a chemically heterogeneous nano-template for self-assembled L1₀FePt nanoparticle arrays

et al. 2016

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“…However, challenges still remain. Annealing or growth temperatures of 450°C or higher are required to obtain nanodots of high PMA L1 0 phases, 14,15 and nanostructuring of L1 0 Mn-Ga required the use of electron beam lithography. 16 These procedures are not ideal for device fabrication.…”

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confidence: 99%

MnxGa1−x nanodots with high coercivity and perpendicular magnetic anisotropy

Karel

Casoli

Lupo

et al. 2016

Applied Surface Science

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A Mn x Ga 1-x (x=0.70) epitaxial thin film with perpendicular magnetic anisotropy and a large coercivity (H c = 1T) was patterned into nanodots using a self-assembly nanolithography procedure. Nanostructuring is achieved by self-assembly of polystyrene nanospheres, which are reduced in size and in turn act as a mask for film etching. This procedure introduced some chemical disorder, which resulted in a soft magnetic component in the magnetic hysteresis loops. However, chemical order was recovered after vacuum annealing at low temperature. The resulting nanodots retain the properties of the original film, i.e. magnetization oriented perpendicular to the particle and large coercivity. Our results suggest this lithography procedure could be a promising direction for preparing spin valve devices.

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“…For example, a directed self-assembly of nanoparticles has been interested because of large area patterning. [13][14][15][16][17] Nonetheless, this technique still has some challenges such as controlling island size distribution, obtaining small island size, and fabricating perfect templates or masks. 18 Besides the island size fluctuation, the written-in error can also be caused by bit island position jitter, main pole position fluctuation, heat spot position, and so forth.…”

Section: Introductionmentioning

confidence: 99%

Investigation of writing error in staggered heated-dot magnetic recording systems

Tipcharoen

Warisarn

Tongsomporn³

et al. 2017

AIP Advances

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To achieve an ultra-high storage capacity, heated-dot magnetic recording (HDMR) has been proposed, which heats a bit-patterned medium before recording data. Generally, an error during the HDMR writing process comes from several sources; however, we only investigate the effects of staggered island arrangement, island size fluctuation caused by imperfect fabrication, and main pole position fluctuation. Simulation results demonstrate that a writing error can be minimized by using a staggered array (hexagonal lattice) instead of a square array. Under the effect of main pole position fluctuation, the writing error is higher than the system without main pole position fluctuation. Finally, we found that the error percentage can drop below 10% when the island size is 8.5 nm and the standard deviation of the island size is 1 nm in the absence of main pole jitter.

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Large-area patterning of sub-100 nm epitaxial L1 FePt dots array via nanoimprint lithography

Cited by 6 publications

References 42 publications

Thermal dewetting with a chemically heterogeneous nano-template for self-assembled L1₀FePt nanoparticle arrays

Thermal dewetting with a chemically heterogeneous nano-template for self-assembled L1₀FePt nanoparticle arrays

MnxGa1−x nanodots with high coercivity and perpendicular magnetic anisotropy

Investigation of writing error in staggered heated-dot magnetic recording systems

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Large-area patterning of sub-100 nm epitaxial L1 FePt dots array via nanoimprint lithography

Cited by 6 publications

References 42 publications

Thermal dewetting with a chemically heterogeneous nano-template for self-assembled L10FePt nanoparticle arrays

Thermal dewetting with a chemically heterogeneous nano-template for self-assembled L10FePt nanoparticle arrays

MnxGa1−x nanodots with high coercivity and perpendicular magnetic anisotropy

Investigation of writing error in staggered heated-dot magnetic recording systems

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Product

Resources

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Thermal dewetting with a chemically heterogeneous nano-template for self-assembled L1₀FePt nanoparticle arrays

Thermal dewetting with a chemically heterogeneous nano-template for self-assembled L1₀FePt nanoparticle arrays