Journal of Magnetism and Magnetic Materials 290–291 (2005) 1580–1583 Insitumonitoringofthemagnetizationrotationofasoftlayer using microwave permeability measurements G. de Temmerman a , H. Pages a , O. Acher a , S. Dubourg a,Ã , F. Schoenstein a , S. Queste a,b , M. Ledieu a a CEA Le Ripault, BP 16, 37260 Monts, France b LEMA UMR 6157 CNRS/CEA, Parc de Grandmont, F-37200 Tours, France Available online 27 December 2004 Abstract Thispaperdemonstratesthatthemonitoringofthemicrowavepermeabilityofthinfilmsisanefficientwaytoobtain a real-time information on the in-plane uniaxial anisotropy, both in magnitude and in direction. Theoretical guidelines requiredtoextractrelevantinformationonthein-planeuniaxialanisotropyarepresented.Thistechniquehasevidenced a fast decrease in the anisotropy followed by a slower rotation process of the uniaxial anisotropy in a Co 91 Nb 6 Zr 3 film during thermo-magnetic annealing. r 2004 Elsevier B.V. All rights reserved. PACS: 75.00.00; 75.30.Gw; 75.60.Nt; 43.20.Ye Keywords: Magnetic properties and materials; Magnetic anisotropy; Magnetic annealing; Measurements 1. Introduction Soft ferromagnetic films are widely used as inductive materials. Most of these materials are annealed after deposition to improve their soft properties. Consider- ableworkhasbeendoneontheannealingofcrystalline, amorphous, and nanocrystalline thin films [1,2].Toour knowledge, the in situ monitoring of the thermal annealing has not gained significant attention, and most investigations on annealing kinetics rely on sample picking after different annealing times and measure- ments at room temperature. The development of magnetic thin films for high frequency applications has induced significant progress in microwave permeability measurement techniques [3]. In particular, high-tem- perature microwave permeability measurements have been recently demonstrated [4]. In this paper, we show the capability of such a technique to measure direction and intensity of uniaxial anistropy changes in a thin Co 91 Nb 6 Zr 3 film during a thermomagnetic treatment. 2. Experimental details We have sputter-deposited amorphous Co 91 Nb 6 Zr 3 thin films onto continuously transported 12 mm thick polyethylene terephatalate (PET) film. During the process, the Ar pressure was fixed at 6  10 3 mbar. The ferromagnetic film thickness was determined to be 1.5 mm. Static magnetic properties were investi- gated using a vibrating sample magnetometer (VSM). The as-grown films exhibit a saturation magnetization ARTICLE IN PRESS www.elsevier.com/locate/jmmm 0304-8853/$-see front matter r 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.jmmm.2004.11.251 Ã Corresponding author. Tel.: +33247344885; fax:+33247345179. E-mail address: sebastien.dubourg@cea.fr (S. Dubourg).