Synthesis and thermal stability of polycrystalline new divalent [beta][double prime]- and [beta]-ferrites prepared by ion exchange

Journal Article · Mon Feb 01 00:00:00 EST 1993 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1006/jssc.1993.1041· OSTI ID:6512473

Kalogirou, O ^[1]

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1. Univ. of Hamburg (Germany) Aristotle Univ., Thessaloniki (Greece)

Using ion-exchange chemistry the divalent cations Ba[sup 2+], Sr[sup 2+], Ca[sup 2+], Mg[sup 2+], Cd[sup 2+], Pb[sup 2+], Co[sup 2+], Zn[sup 2+], Mn[sup 2+], Fe[sup 2+], and Sn[sup 2+] have been substituted for K[sup +] in polycrystalline CdO-stabilized K-[beta][double prime]-ferrite samples. Ba, Sr, Ca, Mg, Pb, and Cd ion exchange led to the synthesis of new materials, the divalent M[sup 2+]-[beta][double prime]-ferrites (M = Ba, Sr, Ca, Mg) and M[sup 2+]-[beta]-ferrites (M = Cd, Pb), respectively. Co[sup 2+]-diffusion resulted in the formation of a spinel-type Co-ferrite. In the case of Zn, Mn, Fe, and Sn the samples decomposed to [alpha]-Fe[sub 2]O[sub 3]. The thermal stability of the new divalent [beta][double prime]- and [beta]-ferrites was studied either by high-temperature exchange reactions or by air annealing of the exchanged products. Ba- and Sr-[beta][double prime]-ferrites and Pb-[beta]-ferrite converted to M-type hexagonal ferrites with the magnetoplumbite structure, Mg-[beta][double prime]-ferrite decomposed to a spinel-type Mg-ferrite, and Ca-[beta][double prime]-ferrite and Cd-[beta]-ferrite decomposed to [alpha]-Fe[sub 2]O[sub 3]. Composition, lattice parameters, SEM photographs, and magnetic properties of the ferrites formed are given. The magnetic susceptibilities of the divalent [beta][double prime]- or [beta]-ferrites have values between 0.63 and 1.14 [times] 10[sup [minus]4] emu/g[center dot]Oe at room temperature. 41 refs., 1 fig., 4 tabs.

• OSTI ID: 6512473
• Journal Information: Journal of Solid State Chemistry; (United States), Vol. 102:2; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
25 ENERGY STORAGE
ALKALINE EARTH METAL COMPOUNDS
THERMAL DEGRADATION
CADMIUM COMPOUNDS
COBALT COMPOUNDS
FERRITES
IRON COMPOUNDS
LEAD COMPOUNDS
MANGANESE COMPOUNDS
TIN COMPOUNDS
ZINC COMPOUNDS
ANNEALING
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CATIONS
CHEMICAL PREPARATION
ION EXCHANGE
LATTICE PARAMETERS
MAGNESIUM COMPOUNDS
MAGNETIC PROPERTIES
SOLID ELECTROLYTES
STRONTIUM COMPOUNDS
X-RAY DIFFRACTION
CHARGED PARTICLES
COHERENT SCATTERING
DIFFRACTION
ELECTROLYTES
FERRIMAGNETIC MATERIALS
HEAT TREATMENTS
IONS
MAGNETIC MATERIALS
MATERIALS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SCATTERING
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
400201* - Chemical & Physicochemical Properties
250903 - Energy Storage- Batteries- Materials
Components
& Auxiliaries