• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>Novel Materials and Processes for Advanced CMOS >Thermal analyses of bulk amorphous oxides and silicates of zirconium and hafnium
【24h】

Thermal analyses of bulk amorphous oxides and silicates of zirconium and hafnium

机译：锆和ha的大块无定形氧化物和硅酸盐的热分析

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Amorphous pure and Y-doped ZrO_2 and HfO_2 were prepared by precipitation with ammonia or hydrazine. Amorphous zirconium and hafnium silicates with SiO_2 content from 10 to 90 mol % were prepared by sol-gel. Crystallization was studied by differential scanning calorimetry (DSC) at 20 ℃/min and crystallite size after crystallization was determined from XRD data. ZrO_2 crystallized into the tetragonal phase with ΔH -21 +- 2 kJ/mol and HfO_2 into the monoclinic phase with ΔH -31 +- 2 kJ/mol. Doping with 20 at% Y decreased crystallite size after crystallization. Crystallization temperatures for pure and Y-doped ZrO_2 samples were in the range 420-440 ℃. Crystallization temperatures for pure and Y-doped HfO_2 samples varied from 470 to 570℃ and correlate with surface area. Crystallization onset temperature in silicates increased with silica content from about 650 to 950 ℃ for ZrO_2·SiO_2 and from 740 to 1030 ℃ for HfO_2·SiO_2. Tetragonal zirconia and hafnia were the only crystalline phases formed below 1100 ℃ in all zirconium silicates and in hafnium silicates with more than 10 mol% SiO_2. Crystallite size after crystallization decreased with increase in silica content. In hafnium silicate, a decrease in HfO_2 crystallite size from 5 to 2.5 +-1 nm corresponds to a crystallization enthalpy change from -22 to -15 +- 2 kJ/mol. The tetragonal HfO_2/amorphous SiO_2 interface energy can be calculated from calorimetric data as ～0.25 J/m~2. The critical particle size for the tetragonal to monoclinic transformation of HfO_2 in HfO_2-SiO_2 system is about 6 nm. We predict that tetragonal HfO_2 will be stabilized in films thinner than 2 nm.
机译：通过用氨或肼沉淀制备无定形的纯Y掺杂ZrO_2和HfO_2。通过溶胶-凝胶法制备了SiO_2含量为10〜90 mol％的非晶硅酸锆和and硅。用差示扫描量热法（DSC）以20℃/ min研究结晶，并根据XRD数据确定结晶后的晶粒尺寸。 ZrO_2以ΔH-21 + -2 kJ / mol结晶为四方晶相，HfO_2以ΔH-31 + -2 kJ / mol结晶为单斜晶相。掺杂20at％的Y可降低结晶后的晶粒尺寸。纯的和掺Y的ZrO_2样品的结晶温度范围为420-440℃。纯的和掺Y的HfO_2样品的结晶温度在470至570℃之间变化，并且与表面积有关。对于ZrO_2·SiO_2，硅酸盐的结晶起始温度随硅含量的增加而从约650升高到950℃，而对于HfO_2·SiO_2则从740升高到1030℃。在所有硅酸锆和含SiO 2大于10 mol％的硅酸and中，四方氧化锆和氧化f是在1100℃以下形成的唯一晶相。结晶后的微晶尺寸随二氧化硅含量的增加而减小。在硅酸ha中，HfO_2晶粒尺寸从5减小到2.5 + -1 nm对应于结晶焓从-22减小到-15 + -2 kJ / mol。从量热数据可以计算出四方HfO_2 /非晶SiO_2界面能为〜0.25J / m〜2。 HfO_2-SiO_2系统中HfO_2由四方转变为单斜晶的临界粒径约为6 nm。我们预测在小于2 nm的薄膜中四方HfO_2将被稳定化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号