scholarly journals Pengaruh lama maturasi pada sintesis biokeramik komposit CaO-TiO2 terhadap ukuran kristal, mikrostruktur dan kekerasan

2021 ◽  
Vol 2 (1) ◽  
pp. 39-47
Author(s):  
M Farid Khoirul Alim ◽  
Hartatiek Hartatiek ◽  
Chusnana Insjaf Yogihati
Keyword(s):  
Crystal Structure ◽  
Vickers Hardness ◽  
Inorganic Crystal Structure Database ◽  
Half Maximum ◽  
Structure Database ◽  
Inorganic Crystal ◽  
Crystal Structure Database

Perkembangan Ilmu Pengetahuan dan Teknologi (IPTEK) akhir-akhir ini mendorong banyaknya inovasi dalam dunia medis terutama penggunaan biomaterial sebagai implan pengganti tulang dan gigi, salah satunya bahan tersebut adalah biokeramik komposit CaO-TiO2. Bahan biokeramik komposit CaO-TiO2 dapat digunakan untuk memperbaiki bagian tubuh yang rusak terutama sebagai implan gigi, penyambung tulang, struktur penahan katup jantung, dan pengganti tulang tengkorak. Paduan antara CaO-TiO2 memiliki beberapa keuntungan diantaranya memiliki biokompatibilitas yang baik, dapat tumbuh serta berkembang bersama-sama dengan tulang asli serta memiliki ketahanan mekanik yang baik. Berdasarkan paparan di atas, tujuan dari penelitian ini adalah mengetahui pengaruh lama maturasi pada biokeramik komposit CaO-TiO2 dengan metode kopresipitasi terhadap kristalinitas, mikrostruktur, dan kekerasan. Pada penelitian ini bahan dasar yang digunakan adalah CaO yang berasal dari batuan kapur alam yang diambil dari pantai Balekambang Kabupaten Malang dan TiO2 dengan kemurnian 99 persen. Sampel dilarutkan dalam aquades dan distirer selama 15 jam pada suhu 70 derajat celcius. Lama maturasi divariasi mulai dari 12, 24, 36, 48, dan 60 jam, dianneling pada suhu 100 derajat celcius selama 24 jam dan disintering selama 4 jam pada suhu 1100 derajat celcius. Sampel dikarakterisasi ukuran kristal, mikrostruktur, dan kekerasan, dengan menggunakan XRD, SEM, dan Micro Vickers Hardness. Hasil analisis CaO-TiO2 menunjukkan kecocokan dan keberhasilan sintesis dengan model pembanding CaO-TiO2 dari Inorganic Crystal Structure Database (ICSD) dengan nilai score diatas 50. Berdasarkan perhitungan teoritik yang dilakukan dengan menentukan nilai FWHM (Full Widht at Half Maximum) dari pola difraksi sampel yang kemudian digunakan pada formula scherrer, diperoleh hasil peningkatan ukuran kristal yang bervariasi terhadap lama maturasi komposit CaO-TiO2 dengan besar antara 45,06 nm-70,85 nm. Dengan meningkatnya ukuran kristal terhadap lama maturasi maka akan disertai oleh peningkatan ukuran butir, sehingga semakin sedikit jumlah pori-pori yang terbentuk pada bahan yang ditunjukan oleh menurunnya nilai luas fraksi pori sebesar 4,97 persen pada lama maturasi 12 jam menjadi 4,79 persen pada lama maturasi 60 jam. Dengan semakin kecilnya nilai fraksi total pori maka semakin besar kekerasan dari bahan tersebut, hal ini ditunjukan dengan nilai kekerasan tertinggi diperoleh pada lama maturasi 60 jam sebesar 497,2 MPa.

Systematic prediction of new ferroelectrics in space groups P31 and P32

2003 ◽  
Vol 59 (5) ◽  
pp. 541-556 ◽  
Author(s):  
S. C. Abrahams
Keyword(s):  
Crystal Structure ◽  
Confidence Level ◽  
Inorganic Crystal Structure Database ◽  
Space Group ◽  
Space Groups ◽  
Structure Database ◽  
Inorganic Crystal ◽  
Atomic Coordinates ◽  
Crystal Structure Database

Release 2002/2 of the Inorganic Crystal Structure Database (FIZ Karlsruhe, Germany, and Institute Laue–Langevin, Grenoble, France) contains 62 entries in space group P31 and ten entries in space group P32 for 49 different materials including eight families with two or more isostructural members. The structural criteria for ferroelectricity are satisfied for 16 new structure types at a confidence level that depends on the reliability of each determination. LaBGeO5, a mineral with stillwellite structure, was previously reported as ferroelectric and forms an additional family with seven other members or related structures that satisfy the criteria. Ten structures reported in space group P31 or P32 are dubious or incorrect, with atomic coordinates that satisfy supergroup symmetry. One material is probably pyroelectric but is unlikely to become ferroelectric, and three others are either incompletely solved or incompletely refined. Among the predicted new ferroelectrics are Cu2BaGeS4, Fe3(Fe,Si)O4(OH)5, Se4S5, K2HCr2AsO10, IV-RbNO3, Rb2Sc(NO3)5, Na3ReO5, Nd14(GeO4)2(BO3)6O8, CsHgCl3, Ba2Cu2AlF11, KYF4, SrS2O6·4H2O, Cu3PbTeO6(OH)2, ReH(CO)4, Ni2(NH3)9Mo(CN)8·2H2O and the 6T polytype of Ca1.89Ta1.80Sm0.16Ti0.10O7, in addition to β-LaBSiO5, PbBAsO5 and BaBAsO5 in the stillwellite family.

Bond analyses of borates from the Inorganic Crystal Structure Database

2006 ◽  
Vol 62 (5) ◽  
pp. 702-709 ◽  
Author(s):  
Daqiu Yu ◽  
Dongfeng Xue
Keyword(s):  
Crystal Structure ◽  
Building Blocks ◽  
Low Complexity ◽  
Bond Valence ◽  
Inorganic Crystal Structure Database ◽  
Bonding Structure ◽  
Structural Evaluation ◽  
Structure Database ◽  
Inorganic Crystal ◽  
Crystal Structure Database

Various fundamental building blocks (FBBs) are observed in the crystallographic structures of oxoborates available in the Inorganic Crystal Structure Database, Version 1.3.3 (2004); the occurrence of borate groups with low complexity is dominant. Bond-valence parameters d 0 of B—O bonds in 758 oxoborates with various FBBs have been calculated using the bond-valence sum model. Some discrepancies in the d 0 values obviously occur if the detailed configurations of FBBs in borate crystals are considered; d 0 is sensitive to the chemical bonding structure of B atoms in the crystallographic framework. Moreover, d 0 values are affected by the existence of interstitial atoms and the substitution of other anionic groups. In addition, the d 0 parameters for B—N, B—S, B—P and B—F bonds are also calculated statistically. Some suitable d 0 data for various borate FBBs are recommended according to their particular configurations, especially for those with low complexity. On the basis of the proposed linear relationship between calculated nonlinear optical (NLO) coefficients of borates and the current d 0 values for various FBBs, it is found that the d 0 values may be regarded as a useful parameter for pre-investigating the NLO properties of borates, leading to an efficient structural evaluation and design of novel borates.

scholarly journals Recent developments in the Inorganic Crystal Structure Database: theoretical crystal structure data and related features

2019 ◽  
Vol 52 (5) ◽  
pp. 918-925 ◽  
Author(s):  
D. Zagorac ◽  
H. Müller ◽  
S. Ruehl ◽  
J. Zagorac ◽  
S. Rehme
Keyword(s):  
Crystal Structure ◽  
Structure Data ◽  
Crystal Structure Data ◽  
Theoretical Data ◽  
Inorganic Crystal Structure Database ◽  
Structure Database ◽  
Inorganic Crystal ◽  
Recent Developments ◽  
New Compounds ◽  
Crystal Structure Database

The Inorganic Crystal Structure Database (ICSD) is the world's largest database of fully evaluated and published crystal structure data, mostly obtained from experimental results. However, the purely experimental approach is no longer the only route to discover new compounds and structures. In the past few decades, numerous computational methods for simulating and predicting structures of inorganic solids have emerged, creating large numbers of theoretical crystal data. In order to take account of these new developments the scope of the ICSD was extended in 2017 to include theoretical structures which are published in peer-reviewed journals. Each theoretical structure has been carefully evaluated, and the resulting CIF has been extended and standardized. Furthermore, a first classification of theoretical data in the ICSD is presented, including additional categories used for comparison of experimental and theoretical information.

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