High‐Density Periodically Ordered Magnetic Cobalt Ferrite Nanodot Arrays by Template‐Assisted Pulsed Laser Deposition

Abstract

A novel nanopatterning method using pulsed laser deposition through an ultrathin anodic aluminium oxide (AAO) membrane mask is proposed to synthesize well‐ordered nanodot arrays of magnetic CoFe2O4 that feature a wide range of applications like sensors, drug delivery, and data storage. This technique allows the adjustment of the array dimension from ∼35 to ∼300 nm in diameter and ∼65 to ∼500 nm in inter‐dot distance. The dot density can be as high as 0.21 Terabit in.−2. The microstructure of the nanodots is characterized by SEM, TEM, and XRD and their magnetic properties are confirmed by well‐defined magnetic force microscopy contrasts and by hysteresis loops recorded by a superconducting quantum interference device. Moreover, the high stability of the AAO mask enables the epitaxial growth of nanodots at a temperature as high as 550 °C. The epitaxial dots demonstrate unique complex magnetic domains such as bubble and stripe domains, which are switchable by external magnetic fields. This patterning method creates opportunities for studying novel physics in oxide nanomagnets and may find applications in spintronic devices.

Effect of the thermal treatment on the magnetic and structural properties of cobalt ferrite particles

“…Spinel ferrites (MFe 2 O 4 ) have hereof been in the spotlight of many research groups for their applicability in modern electric devices, [2] such as sensors [3], memories [4] and in the medical field. [5] Owing to their high coercivity, moderate saturation magnetization, [6] mechanical hardness and excellent chemical stability, [7,8] these materials are nowadays highly popular for applications in magnetic and magneto-optical devices.…”

Skyrmion-like bubbles and stripes in a thin ferromagnetic film with lattice of antidots

“…They can be used in applications for transmission and/or storage of information. Among different topological excitations, the so-called skyrmions attract recently a lot of attention [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. They were first found theoretically by Skyrme during investigation in the field of nuclear physics [17].…”

Tunable magnetic anisotropy of CoFe2O4 nanopillar arrays released from BiFeO3 matrix

“…Nanoarrays of ferromagnetic materials are important for the fabrication of magnetic recording and spintronic devices. Traditional lithography was developed for patterning of semiconductors, and there are only a few reports on patterned oxide magnets by this method due to their chemical inertness 14. To solve this problem, anodized aluminum oxide templates have been used for the fabrication of high density CFO nanoarrays 14–16.…”