Low-temperature sintering and magnetic properties of Sc- and In-substituted M-type hexagonal barium ferrites for microwave applications. (February 2017)

• Record Type: Journal Article
• Authors: Bierlich, Silvia; Gellersen, Frauke; Jacob, Arne; Töpfer, Jörg
• Is Part Of: Materials research bulletin. Volume 86(2017)
• Page Start: 19
• Page End: 23
• Publication Date: 2017-02
• Subjects: Oxides -- Magnetic materials -- Magnetic properties -- Multilayers -- Microwave ferrites; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2016.09.025
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: Solid solution of Sc- and In-substituted BaFe12-x Mex O19 between 0 ≤ x ≤ 2. Low-temperature sintering of ferrites at T = 900 °C using a BBSZ glass additive. Reduction of saturation magnetization and coercivity with x. Decrease of resonance frequency from 45 to 20 GHz with increasing substitution x. LTCC-compatible substituted hexagonal ferrites with resonance frequency in Ka band. Abstract: Partial substitution of Fe 3+ by Sc 3+ or In 3+ in M-type ferrite is an effective method to tailor their anisotropy field and resonance frequency. BaMe x Fe12- x O19 with Me = Sc and In (0 ≤ x ≤ 2) was synthesized by the mixed-oxide route. XRD revealed a continuous increase of the hexagonal lattice parameters with substitution rate x. Both, the saturation magnetization and coercivity at room temperature are reduced with x. The ferromagnetic resonance frequency decreases from 48 GHz at x = 0 to 30 GHz at x = 0.5 for Sc-substituted ferrites. For In-substitution, a smaller reduction of the resonance frequency with x is observed, e.g. to 37 GHz at x = 0.5. Addition of BBSZ glass allows sintering at 900 °C. Low-temperature fired samples exhibit ferromagnetic resonance at the same frequencies and represent promising materials for self-biased microwave components for integration into LTCC multilayer modules.