Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the main phases and the crystal boundary phases among the R2T14B crystal grains. The microstructure of the sintered body is controlled by including crystal boundary phases containing at least R, T and M in the crystal boundary phases, wherein the relative atomic ratios of R, T and M are as follows, i.e., 25 to 35% for R, 60 to 70% for T and 2 to 10% for M.

Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the main phases and the crystal boundary phases among R2T14B crystal grains. The microstructure of the sintered body is controlled by at least containing the first crystal boundary phases and the second crystal boundary phases, wherein the first crystal boundary phases contain at least R-T-M in the ranges of 20 to 40 atomic % for R, 60 to 75 atomic % for T and 1 to 10 atomic % for M, and the second crystal boundary phases contains at least R-T-M in the ranges of 50 to 70 atomic % for R, 10 to 30 atomic % for T and 1 to 20 atomic % for M.

Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the major phases and the crystal boundary phases among the R2T14B crystal grains. The microstructure of the sintered body is controlled by including crystal boundary phases containing at least R, T and M in the crystal boundary phases, wherein the relative atomic ratios of R, T and M are as follows, i.e., 60 to 80% for R, 15 to 35% for T and 1 to 20% for M.

Abstract: 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.

Abstract: The present invention provides a rare earth based magnet that inhibits the high temperature demagnetization rate even when less or no heavy rare earth elements such as Dy, Tb and the like are used. The rare earth based magnet according to the present invention includes R2T14B main phase crystal grains and grain boundary phases between adjacent main phase crystal grains. In any cross-section of the rare earth based magnet, when evaluating the circular degree of the main phase crystal grains with Wadell's Roundenss A, the shape of the main phase crystal grains is controlled such that the Roundness A becomes 0.24 or more.

Abstract: The present invention provides a rare earth based magnet having a microstructure in which in a section of the R2T14B main-phase crystal grains, the number density of the fine products in the interior of (inside) the crystal grains is larger than that in the periphery of (outside) the crystal grains. That is, the rare earth based magnet includes R2T14B main-phase crystal grains and grain boundary phases formed between the R2T14B main-phase crystal grains. The R2T14B main-phase crystal grains include a substance where fine products are formed in the crystal grains. In the section of the main-phase crystal grains, when the crystal grains are divided into the interior of the crystal grains and the periphery of the crystal grains with a specific ellipse, the fine products are formed such that the number density in the interior is larger than that in the periphery.

Abstract: The present invention provides a rare earth based magnet including R2T14B main-phase crystal grains, and two-grain boundary phases between adjacent two R2T14B main-phase crystal grains, the two-grain boundary phases are controlled such that the thickness thereof is 5 nm or more and 500 nm or less, and it is composed of a phase with a magnetism different from that of a ferromagnet.

Abstract: An R-T-B based sintered magnet maintains high magnetic properties and decreases usage of heavy rare earth elements. The magnet includes main phase grains and grain boundary phases, the main phase grain containing a core portion and a shell portion. X in the main phase LR(2-x)HRxT14B of the core portion ranges from 0.00 to 0.07; x in the main phase LR(2-x)HRxT14B of the shell portion ranges from 0.02 to 0.40; and the maximum thickness of the shell portion ranges from 7 nm to 100 nm. LR contains Nd and one or more light rare earth elements consisting of Y, La, Ce, Pr and Sm; HR contains Dy or/and Tb and one or more heavy rare earth elements consisting of Gd, Ho, Er, Tm, Yb and Lu; T contains Fe or/and Co and one or two kinds of Mn and Ni; and B represents boron partly replaced by C (carbon).

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention provides a ferrite magnetic material capable of attaining such magnetic properties that Br+(?)HcJ is 6200 or more even by sintering at a temperature of 1150° C. or lower. The ferrite magnetic material includes as a main phase thereof a ferrite phase having a hexagonal structure, the main phase being represented by the following composition formula (1): LaxCam?1?x?m(Fe12?yCoy)z with ? representing one or two of Ba and Sr; wherein the constituent ratios of the metal elements constituting the main phase satisfy the following conditions: x and m are the values in a region bounded by the points, A: (0.53, 0.27), B: (0.64, 0.27), C: (0.64, 0.35), D: (0.53, 0.45), E: (0.47, 0.45) and F: (0.47, 0.32) in the (x, m) coordinates shown in FIG. 2; 1.3?x/yz?1.8; and 9.5?12z?11.0.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A ceramic material powder comprised of main ingredient particles formed by barium titanate having on their surfaces a covering layer comprised of a secondary ingredient additive, wherein when an average radius of the main ingredient particles is “r” and an average radius of the covering layer is “?r”, the ?r is controlled to a range of 0.015 r to 0.055 r, thereby enabling acquisition of a multilayer ceramic capacitor or other electronic device satisfying both the X7R characteristic prescribed in the EIAJ standard and B characteristic prescribed in the Japan Industrial Standard (JIS), that is, excellent in temperature stability of the electrostatic capacity, having a good insulation resistance value, relative dielectric constant, or other characteristics, and having a long accelerated life of the insulation resistance.

Abstract: 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.

Abstract: A sintered body comprising a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co), and a grain boundary phase containing a higher amount of R than the main phase, wherein a platy or acicular product exists. This sintered body enables to inhibit the grain growth, while keeping a decrease in magnetic properties to a minimum, and to improve a suitable sintering temperature range.

Abstract: 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.

Abstract: The present invention provides a ferrite magnetic material capable of attaining such magnetic properties that Br+(?)HcJ is 6200 or more even by sintering at a temperature of 1150° C. or lower. The ferrite magnetic material includes as a main phase thereof a ferrite phase having a hexagonal structure, the main phase being represented by the following composition formula (1): LaxCam?1?x?m(Fe12?yCoy)z with ? representing one or two of Ba and Sr; wherein the constituent ratios of the metal elements constituting the main phase satisfy the following conditions: x and m are the values in a region bounded by the points, A: (0.53, 0.27), B: (0.64, 0.27), C: (0.64, 0.35), D: (0.53, 0.45), E: (0.47, 0.45) and F: (0.47, 0.32) in the (x, m) coordinates shown in FIG. 2; 1.3?x/yz?1.8; and 9.5?12z?11.0.