US 11,851,375 B2
Ceramic complex and method for producing the same
Toshiyuki Hirai, Komatsushima (JP); Keisuke Suzuki, Anan (JP); and Hirofumi Oguri, Komatsushima (JP)
Assigned to NICHIA CORPORATION, Anan (JP)
Filed by NICHIA CORPORATION, Anan (JP)
Filed on Jun. 29, 2021, as Appl. No. 17/304,956.
Claims priority of application No. 2020-113289 (JP), filed on Jun. 30, 2020.
Prior Publication US 2021/0403382 A1, Dec. 30, 2021
Int. Cl. C04B 35/10 (2006.01); C04B 35/64 (2006.01); C04B 35/44 (2006.01); C09K 11/77 (2006.01); C04B 35/117 (2006.01); C04B 35/645 (2006.01); C04B 111/80 (2006.01)
CPC C04B 35/10 (2013.01) [C04B 35/117 (2013.01); C04B 35/44 (2013.01); C04B 35/64 (2013.01); C04B 35/6455 (2013.01); C09K 11/7774 (2013.01); C04B 2111/807 (2013.01); C04B 2235/3222 (2013.01); C04B 2235/3224 (2013.01); C04B 2235/3225 (2013.01); C04B 2235/3227 (2013.01); C04B 2235/661 (2013.01); C04B 2235/662 (2013.01); C04B 2235/77 (2013.01); C04B 2235/78 (2013.01); C04B 2235/786 (2013.01); C04B 2235/963 (2013.01)] 7 Claims
 
1. A ceramic complex, comprising
a first crystal phase that contains a first rare earth aluminate fluorescent material containing an activating element and a first rare earth element different from the activating element,
a second crystal phase comprising a second rare earth aluminate containing a second rare earth element, wherein a content of an element capable of being an activator in the second crystal phase is 200 ppm by mass or less, and
a third crystal phase comprising aluminum oxide,
wherein a content of the first crystal phase is in a range of 5% by volume or more and 45% by volume or less, a content of the second crystal phase is in a range of 0.5% by volume or more and 50% by volume or less, and a content of the third crystal phase is the balance, relative to 100% by volume of a total amount of the first crystal phase, the second crystal phase, and the third crystal phase, and
wherein a first crystal diameter G1 of the first crystal phase is in a range of 5 μm or more and 40 μm or less, and a second crystal diameter G2 of the second crystal phase is in a range of 0.5 μm or more and less than 5 μm, as measured under the following measurement conditions:
in a scanning electron microscope (SEM) image obtained by photographing a cross section of the ceramic complex using an SEM, the maximum width in the cross section of the first crystal phase or the second crystal phase, and the minimum width passing through a center point of the maximum width are measured; an average of the maximum width and the minimum width is defined as a diameter for each of the first crystal phase and the second crystal phase; and an average value of the diameters of 20 first crystal phases or second crystal phases randomly selected is regarded as the first crystal diameter G1 of the first crystal phase or the second crystal diameter G2 of the second crystal phase.