GOULD, DANIEL A.QUINLAN, MERVINALBANO, MARIA P.GARRIDO, LILIANA B.GENOVA, LUIS A.PLUCKNETT, KEVIN P.2014-07-152014-07-302014-07-152014-07-302009GOULD, DANIEL A.; QUINLAN, MERVIN; ALBANO, MARIA P.; GARRIDO, LILIANA B.; GENOVA, LUIS A.; PLUCKNETT, KEVIN P. A simple method for synthesis of acicular β-Si3N4 seed crystals. <b>Ceramics International</b>, v. 35, n. 4, p. 1357-1362, 2009. DOI: <a href="https://dx.doi.org/10.1016/j.ceramint.2008.07.013">10.1016/j.ceramint.2008.07.013</a>. Disponível em: http://repositorio.ipen.br/handle/123456789/4836.0272-8842http://repositorio.ipen.br/handle/123456789/4836Acicular silicon nitride (β-Si3N4) seed crystals have been synthesized using a moderately low temperature heat-treatment process, with the aid of a low volume fraction of multiple sintering aids (i.e. MgO and CaO, in combination with either Y2O3 or Nd2O3). The effects of the heat-treatment cycle and the additive composition on the α- to β-Si3N4 phase transformation were examined, for both cold-isostatically pressed pellets and simple packed powder. In the case of the packed powder, full transformation was achievable following heat-treatment at 1625 °C for four hours, in ∼0.1 MPa nitrogen. The use of multiple oxide additives allows seed liberation from the heat-treated materials using a simple dilute HF soak at room temperature. The resulting β-Si3N4 seed crystals exhibit a narrow size distribution, with mean aspect ratios of ∼4:1.1357-1362openAccesssilicon nitridessynthesisceramicscrystalsheat treatmentsphase transformationsaspect ratioArtigo de periódico43510.1016/j.ceramint.2008.07.013https://orcid.org/0000-0002-5172-5082