A magnetizable glass ceramic composition including: a continuous first glass phase including SiO.sub.2, B.sub.2O.sub.3, P.sub.2O.sub.5, and R.sub.2O; a discontinuous second glass phase including at least one of SiO.sub.2, B.sub.2O.sub.3, P.sub.2O.sub.5, R.sub.2O, or mixtures thereof; and a discrete magnetizable crystalline phase dispersed in the discontinuous second glass phase, where R.sub.2O is selected from at least one of K.sub.2O, Li.sub.2O, Na.sub.2O, or mixtures thereof. Also disclosed are a method of making and a method of using the magnetizable glass ceramic composition.

Embodiments of the present disclosure pertain to crystallizable glasses and glass-ceramics that exhibit a black color and are opaque. In one or more embodiments, the crystallizable glasses and glass-ceramics include a precursor glass composition that exhibits a liquidus viscosity of greater than about 20 kPa*s. The glass-ceramics exhibit less than about 20 wt % of one or more crystalline phases, which can include a plurality of crystallites in the Fe.sub.2O.sub.3—TiO.sub.2—MgO system and an area fraction of less than about 15%. Exemplary compositions used in the crystallizable glasses and glass-ceramics include, in mol %, SiO.sub.2 in the range from about 50 to about 76, Al.sub.2O.sub.3 in the range from about 4 to about 25, P.sub.2O.sub.5+B.sub.2O.sub.3 in the range from about 0 to about 14, R.sub.2O in the range from about 2 to about 20, one or more nucleating agents in the range from about 0 to about 5, and RO in the range from about 0 to about 20.

Embodiments of the present disclosure pertain to crystallizable glasses and glass-ceramics that exhibit a black color and are opaque. In one or more embodiments, the crystallizable glasses and glass-ceramics include a precursor glass composition that exhibits a liquidus viscosity of greater than about 20 kPa*s. The glass-ceramics exhibit less than about 20 wt % of one or more crystalline phases, which can include a plurality of crystallites in the Fe.sub.2O.sub.3TiO.sub.2MgO system and an area fraction of less than about 15%. Exemplary compositions used in the crystallizable glasses and glass-ceramics include, in mol %, SiO.sub.2 in the range from about 50 to about 76, Al.sub.2O.sub.3 in the range from about 4 to about 25, P.sub.2O.sub.5+B.sub.2O.sub.3 in the range from about 0 to about 14, R.sub.2O in the range from about 2 to about 20, one or more nucleating agents in the range from about 0 to about 5, and RO in the range from about 0 to about 20.

Embodiments of the present disclosure pertain to crystallizable glasses and glass-ceramics that exhibit a black color and are opaque. In one or more embodiments, the crystallizable glasses and glass-ceramics include a precursor glass composition that exhibits a liquidus viscosity of greater than about 20 kPa*s. The glass-ceramics exhibit less than about 20 wt % of one or more crystalline phases, which can include a plurality of crystallites in the Fe.sub.2O.sub.3TiO.sub.2MgO system and an area fraction of less than about 15%. Exemplary compositions used in the crystallizable glasses and glass-ceramics include, in mol %, SiO.sub.2 in the range from about 50 to about 76, Al.sub.2O.sub.3 in the range from about 4 to about 25, P.sub.2O.sub.5+B.sub.2O.sub.3 in the range from about 0 to about 14, R.sub.2O in the range from about 2 to about 20, one or more nucleating agents in the range from about 0 to about 5, and RO in the range from about 0 to about 20.

A glass-ceramic-ferrite composition contains glass, a ceramic filler, and NiZnCu ferrite. The glass contains about 0.5% by weight or more of R.sub.2O, where R is at least one selected from the group consisting of Li, Na, and K; about 5.0% by weight or less of Al.sub.2O.sub.3; about 10.0% by weight or more of B.sub.2O.sub.3; and about 85.0% by weight or less of SiO.sub.2 on the basis of the weight of the glass. The NiZnCu ferrite accounts for about 58% to 64% by weight of the glass-ceramic-ferrite composition. The ceramic filler contains quartz and, in some cases, forsterite. The quartz accounts for about 4% to 13% by weight of the glass-ceramic-ferrite composition. The forsterite accounts for about 6% by weight or less of the glass-ceramic-ferrite composition.

A glass-ceramic-ferrite composition contains glass, a ceramic filler, and NiZnCu ferrite. The glass contains about 0.5% by weight or more of R.sub.2O, where R is at least one selected from the group consisting of Li, Na, and K; about 5.0% by weight or less of Al.sub.2O.sub.3; about 10.0% by weight or more of B.sub.2O.sub.3; and about 85.0% by weight or less of SiO.sub.2 on the basis of the weight of the glass. The NiZnCu ferrite accounts for about 58% to 64% by weight of the glass-ceramic-ferrite composition. The ceramic filler contains quartz and, in some cases, forsterite. The quartz accounts for about 4% to 13% by weight of the glass-ceramic-ferrite composition. The forsterite accounts for about 6% by weight or less of the glass-ceramic-ferrite composition.

A glass-ceramic substrate includes a continuous glass phase; a magnetizable component; and an antimicrobial component. The substrate can further include a discontinuous glass phase disposed in the continuous glass phase. The magnetizable component and the antimicrobial component can be disposed in the discontinuous glass phase. The substrate can include 45 percent to 60 percent SiO.sub.2; 3 percent to 6 percent P.sub.2O.sub.5; 3 percent to 10 percent B.sub.2O.sub.3; 4 percent to 8 percent K.sub.2O; 7 percent to 15 percent Fe.sub.2O.sub.3; and 15 percent to 25 percent CuO. A ratio of the mole percentage of CuO to Fe.sub.2O.sub.3 in the substrate can be 1.3 to 3.0. The magnetizable component can include one or more of delafossite and magnetite. The antimicrobial component can include one or more of cuprite and metallic copper. The substrate can exhibit a magnetic permeability of greater than or equal to 1.02?.sub.R at a frequency of 10,000,000 Hz.

A magnetizable glass ceramic composition including: a continuous first glass phase including SiO.sub.2, B.sub.2O.sub.3, P.sub.2O.sub.5, and R.sub.2O; a discontinuous second glass phase including at least one of SiO.sub.2, B.sub.2O.sub.3, P.sub.2O.sub.5, R.sub.2O, or mixtures thereof; and a discrete magnetizable crystalline phase dispersed in the discontinuous second glass phase, where R.sub.2O is selected from at least one of K.sub.2O, Li.sub.2O, Na.sub.2O, or mixtures thereof. Also disclosed are a method of making and a method of using the magnetizable glass ceramic composition.

Embodiments of the present disclosure pertain to crystallizable glasses and glass-ceramics that exhibit a black color and are opaque. In one or more embodiments, the crystallizable glasses and glass-ceramics include a precursor glass composition that exhibits a liquidus viscosity of greater than about 20 kPa*s. The glass-ceramics exhibit less than about 20 wt % of one or more crystalline phases, which can include a plurality of crystallites in the Fe.sub.2O.sub.3TiO.sub.2MgO system and an area fraction of less than about 15%. Exemplary compositions used in the crystallizable glasses and glass-ceramics include, in mol %, SiO.sub.2 in the range from about 50 to about 76, Al.sub.2O.sub.3 in the range from about 4 to about 25, P.sub.2O.sub.5+B.sub.2O.sub.3 in the range from about 0 to about 14, R.sub.2O in the range from about 2 to about 20, one or more nucleating agents in the range from about 0 to about 5, and RO in the range from about 0 to about 20.

Embodiments of the present disclosure pertain to crystallizable glasses and glass-ceramics that exhibit a black color and are opaque. In one or more embodiments, the crystallizable glasses and glass-ceramics include a precursor glass composition that exhibits a liquidus viscosity of greater than about 20 kPa*s. The glass-ceramics exhibit less than about 20 wt % of one or more crystalline phases, which can include a plurality of crystallites in the Fe.sub.2O.sub.3TiO.sub.2MgO system and an area fraction of less than about 15%. Exemplary compositions used in the crystallizable glasses and glass-ceramics include, in mol %, SiO.sub.2 in the range from about 50 to about 76, Al.sub.2O.sub.3 in the range from about 4 to about 25, P.sub.2O.sub.5+B.sub.2O.sub.3 in the range from about 0 to about 14, R.sub.2O in the range from about 2 to about 20, one or more nucleating agents in the range from about 0 to about 5, and RO in the range from about 0 to about 20.