Disclosed is a ceramic sintered body comprising magnesium aluminate spinel of composition MgAl.sub.2O.sub.4 having from 90 to 100% by volume of a cubic crystallographic structure and a density of from 3.47 to 3.58 g/cc, wherein the ceramic sintered body is free of sintering aids. A method of making the ceramic sintered body comprising spinel is also disclosed.

Disclosed is a ceramic sintered body comprising magnesium aluminate spinel of composition MgAl.sub.2O.sub.4 having from 90 to 100% by volume of a cubic crystallographic structure and a density of from 3.47 to 3.58 g/cc, wherein the ceramic sintered body is free of sintering aids. A method of making the ceramic sintered body comprising spinel is also disclosed.

The present invention aims to obtain a resin composition with low thermal expansion property by suppressing functional deterioration in negative thermal expansion property when a negative thermal expansion material is added to a thermoplastic resin and heat-processed. The present invention provides a resin composition including metal oxide particles and a thermoplastic resin, both having a negative thermal expansion property. The negative thermal expansion of the particles is attributed to a crystal phase transition, which is driven by electron transfer between the constituent metals, and a covalent protective layer that inhibits the electron transfer is formed between the particles and the thermoplastic resin.

A one-step salt-assisted general synthetic methodology for the controlled phase transformation of various types of 2H-phase transition metal dichalcogenides (2H-TMDs), yielding large-scale metastable 1T-phase transition metal dichalcogenides (1T-TMDs), including WS.sub.2, WSe.sub.2, MoS.sub.2, and MoSe.sub.2 is described. By tuning the reaction conditions, alloyed 1T-TMDs such as WS.sub.2xSe.sub.2(1x) and MoS.sub.2xSe.sub.2(1x) are also obtained. Commercially-available metal salts such as K.sub.2C.sub.2O.sub.4.Math.H.sub.2O, Na.sub.2C.sub.2O.sub.4, K.sub.2CO.sub.3, Na.sub.2CO.sub.3, Cs.sub.2CO.sub.3, Rb.sub.2CO.sub.3, KHCO.sub.3, and NaHCO.sub.3, are demonstrated to be effective for the controlled phase transformation at elevated temperatures in a reducing atmosphere. The technique may be extended to the phase engineering of other materials with various polymorphs.