摘要:
A magnetic body which can reversibly change its magnetic force with a small external magnetic field while having a high residual magnetic flux density is provided. The magnetic body of the present invention has a residual magnetic flux density Br of at least 11 kG and a coercive force HcJ of 5 kOe or less, while an external magnetic field required for the residual magnetic flux density Br to become 0 is 1.10 HcJ or less.
摘要:
A core/shell structured powder different in composition between the inside the particle and the surface thereof before sintering, so that it is possible to sinter the powder at lower temperature and give a core/shell structured powder having a shell portion uniform in thickness after sintering; a multilayered ceramic capacitor having a longer lifetime, by preparing the multilayered ceramic capacitor by using a powder having a core/shell structure different in composition between the inside the particle and the surface thereof before sintering; and a method of producing a powder by synthesizing particles in the liquid containing a raw material, wherein particles different in composition at least between the inside the particle and the surface thereof are obtained by adding a composition to be incorporated as a component of the particles to the liquid during the synthetic process so that the composition of the liquid changes continuously or intermittently.
摘要:
A method of producing fine and uniform barium titanate particles having high crystallinity by performing a heat treatment on titanium dioxide and barium carbonate having a specific surface area of at least 20 m2/g and low rutile ratio; comprising the steps of preparing mixed powder by mixing titanium dioxide particles having a rutile ratio of 30% or lower and a specific surface area of 20 m2/g or more and barium carbonate particles, a first heat treatment step for performing a heat treatment on the mixed powder to generate a barium titanate phase having an average thickness of at least 3 nm continuously on surfaces of titanium dioxide particles by an amount of 15 wt % or more, and a second heat treatment step for performing a heat treatment at 800° C. to 1000° C.
摘要:
An active material with a sufficient cycle characteristic and a process for its production are provided. According to the process for production of an active material of this invention, an aqueous solution containing a metal fluorocomplex is contacted with a metal oxide to form a surface-modified layer on the surface of the metal oxide. The active material of the invention comprises a core section made of a metal oxide and a surface-modified layer covering the core section, wherein the surface-modified layer is an oxide containing a metal present in the core section and a metal not present in the core section.
摘要:
A sintered body with a composition consisting of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, provided that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe. This sintered body has a coefficient of variation (CV value) showing the dispersion degree of Zr of 130 or less. In addition, this sintered body has a grain boundary phase comprising a region that is rich both in at least one element selected from a group consisting of Cu, Co and R, and in Zr. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.
摘要:
One embodiment of the present invention is that in samarium-iron-nitrogen magnet powder, a non-magnetic phase is formed on a surface of the samarium-iron-nitrogen magnet phase, and an arithmetic mean roughness Ra of the surface is 3.5 nm or less.
摘要:
An active material with a sufficient cycle characteristic and a process for its production are provided. According to the process for production of an active material of this invention, an aqueous solution containing a metal fluorocomplex is contacted with a metal oxide to form a surface-modified layer on the surface of the metal oxide. The active material of the invention comprises a core section made of a metal oxide and a surface-modified layer covering the core section, wherein the surface-modified layer is an oxide containing a metal present in the core section and a metal not present in the core section.
摘要:
A multilayer ceramic capacitor 1 having dielectric layers 2 having barium titanate or barium calcium titanate as a main ingredient. When the dielectric layers are barium titanate, the ratio of the grains having a thickness of the crystal grain boundaries 22 present between adjoining dielectric grains 20 is 30% to 95% of the plurality of dielectric grains 20 forming the dielectric layers 2. When the dielectric layers 2 are barium calcium titanate, the ratio of the grains having a thickness of the crystal grain boundaries 22 present between adjoining dielectric grains 20 is 20% to 70% of the plurality of dielectric grains 20 forming the dielectric layers 2.
摘要:
An object of the present invention is to make a core/shell structured powder different in composition between the inside the particle and the surface thereof before sintering, so that it is possible to sinter the powder at lower temperature and give a core/shell structured powder having a shell portion uniform in thickness after sintering. Another object of the present invention is to provide a multilayered ceramic capacitor having a longer lifetime, by preparing the multilayered ceramic capacitor by using a powder having a core/shell structure different in composition between the inside the particle and the surface thereof before sintering. The method of producing a powder according to the invention is a method of producing a powder by synthesizing particles in the liquid containing a raw material, wherein particles different in composition at least between the inside the particle and the surface thereof are obtained by adding a composition to be incorporated as a component of the particles to the liquid during the synthetic process so that the composition of the liquid changes continuously or intermittently.
摘要:
The present invention provides a sintered magnet having superior residual magnetic flux density and coercive force. The sintered magnet of the present invention comprises a group of R-T-B based rare earth magnet crystal particles 2 having a core 4 and a shell 6 covering the core 4, the mass ratio of a heavy rare earth element in the shell 6 is higher than the mass ratio of a heavy rare earth element in the core 4, and the thickest part of the shell 6 in the crystal particles 2 faces a grain boundary triple junction 1. A lattice defect 3 is formed between the core 4 and the shell 6.