Atomic layer deposition of nickel–cobalt spinel thin films. Issue 14 (27th March 2017)

• Record Type: Journal Article
• Authors: Hagen, D. J.; Tripathi, T. S.; Karppinen, M.
• Is Part Of: Dalton transactions. Volume 46:Issue 14(2017)
• Page Start: 4796
• Page End: 4805
• Publication Date: 2017-03-27
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c7dt00512a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Combining ALD cycles for NiO and Co3 O4, (Co1− x Ni x )3 O4 films with a wide range of electrical and magnetic properties are obtained. Abstract : We report the atomic layer deposition (ALD) of high-quality crystalline thin films of the spinel-oxide system (Co1− x Ni x )3 O4 . These spinel oxides are ferrimagnetic p-type semiconductors, and promising material candidates for several applications ranging from photovoltaics and spintronics to thermoelectrics. The spinel phase is obtained for Ni contents exceeding the x = 0.33 limit for bulk samples. It is observed that the electrical resistivity decreases continuously with x while the magnetic moment increases up to x = 0.5. This is in contrast to bulk samples where a decrease of resistivity is not observed for x > 0.33 due to the formation of a rock-salt phase. From UV-VIS-NIR absorption measurements, a change from distinct absorption edges for the parent oxide Co3 O4 to a continuous absorption band ranging deep into the near infrared for 0 < x ≤ 0.5 was observed. The conformal deposition of dense films on high-aspect-ratio patterns is demonstrated.