Tuning of the Titanium Oxide Surface to Control Magnetic Properties of Thin Iron Films

Abstract

We describe the magnetic properties of thin iron films deposited on the nanoporous titanium oxide templates and analyze their dependance on nanopore radius. We then compare the results to a continuous iron film of the same thickness. Additionally, we investigate the evolution of the magnetic properties of these films after annealing. We demonstrate that the M(H) loops consist of two magnetic phases originating from the iron layer and iron oxides formed at the titanium oxide/iron interface. We perform deconvolution of hysteresis loops to extract information for each magnetic phase. Finally, we investigate the magnetic interactions between the phases and verify the presence of exchange coupling between them. We observe the altering of the magnetic properties by the nanopores as a magnetic hardening of the magnetic material. The ZFC-FC (Zero-field cooled/field cooled) measurements indicate the presence of a disordered glass state below 50 K, which can be explained by the formation of iron oxide at the titanium oxide-iron interface with a short-range magnetic order.

Manipulating Electrical Properties of Nanopatterned Double-Barrier Schottky Junctions in Ti/TiOx/Fe Systems

“…Larger pores have larger working surface, and oxidation of Fe results in larger amount of iron oxide at the ATO/Fe interface which may influence the transport properties. We have already seen the effect of pore size-dependent oxidation at the nanopatterned samples by the investigation the magnetic properties in this type of junctions . Additionally, at low temperatures, a minimum in the MR for nanoporous samples is present (marked with a purple bar in Figure ).…”

“…The electrolytes were aged for 24 h to homogenize the solution and to slow the electrochemical etching/oxidation processes. We used three different anodization voltages of 5, 15, and 60 V, and anodization time was 45 min based on the results of our previous experiments. , After fabrication of anodized titanium oxide, the samples were covered with 50 nm of iron followed by 50 nm of gold. The protective gold layer prevented ambient oxidation and was simultaneously the top electrical contact.…”

“…21 In this paper, we describe a concept of the junctions with patterned oxide semiconductors and a magnetic layer of iron, the idea which was tested in our previous studies. 22,23 Metal/titanium oxide/metal junctions exhibit a wide range of electrical conducting properties, from insulating through semiconducting to Ohmic. These properties strongly depend on the metal and on the type of barrier formed at the metal/ TiO 2 interface.…”

“…The anodized titanium oxides are popular substrates for formation of nanopatterned thin films . In this paper, we describe a concept of the junctions with patterned oxide semiconductors and a magnetic layer of iron, the idea which was tested in our previous studies. , …”

“…We have already seen the effect of pore size-dependent oxidation at the nanopatterned samples by the investigation the magnetic properties in this type of junctions. 23 Additionally, at low temperatures, a minimum in the MR for nanoporous samples is present (marked with a purple bar in Figure 7).…”