β-cubic phase transition of scandia-doped zirconia solid solution: Calorimetry, x-ray diffraction, and Raman scattering

2002 ◽  
Vol 91 (10) ◽  
pp. 6493 ◽  
Author(s):  
Hirotaka Fujimori ◽  
Masatomo Yashima ◽  
Masato Kakihana ◽  
Masahiro Yoshimura
2005 ◽  
Vol 74 (8) ◽  
pp. 2165-2168 ◽  
Author(s):  
Yoichi Okimoto ◽  
Reiji Kumai ◽  
Sachio Horiuchi ◽  
Hiroshi Okamoto ◽  
Yoshinori Tokura

2011 ◽  
Vol 687 ◽  
pp. 677-683 ◽  
Author(s):  
Fei Ming Bai ◽  
Huai Wu Zhang ◽  
Surendra Gupta ◽  
Santosh Kurinec

Phase transitions in stacked GeTe/SnTe and Ge2Se3/SnTe thin layers for potential phase-change memory applications have been investigated by X-ray diffraction using an area detector system and by scanning electron microscopy. The as-deposited underlying GeTe or Ge2Se3 layer is amorphous, whereas the top SnTe layer is crystalline. In GeTe/SnTe stack, the crystallization of GeTe phase occurs near 170°C, and upon further heating, GeTe phase disappears, followed by the formation of rocksalt-structured GexSn1-xTe solid solution. In Ge2Se3/SnTe stack, the phase transition starts with the separation of SnSe phase due to the migration of Sn ions into the Ge2Se3 layer. The migration of Sn ions and the formation of SnSe are believed to facilitate the crystallization of Ge2Se3 solid solution at ~360°C, which is much lower than the crystallization temperature of Ge2Se3, therefore consuming less power during the phase transition.


Langmuir ◽  
2010 ◽  
Vol 26 (14) ◽  
pp. 11605-11608 ◽  
Author(s):  
Hiroyuki Mori ◽  
Shoichi Kutsumizu ◽  
Kazuya Saito ◽  
Katsuhiro Yamamoto ◽  
Shinichi Sakurai ◽  
...  

2001 ◽  
Vol 57 (3) ◽  
pp. 221-230 ◽  
Author(s):  
A. Guelylah ◽  
G. Madariaga ◽  
V. Petricek ◽  
T. Breczewski ◽  
M. I. Aroyo ◽  
...  

The potassium manganese tetrafluoroberyllate langbeinite compound has been studied in the temperature range 100–300 K. Using DSC measurements, a phase transition has been detected at 213 K. The space group of the low-temperature phase was determined to be P1121 using X-ray diffraction experiments and optical observations of the domain structure. The b axis is doubled with respect to the prototypic P213 cubic phase. Lattice parameters were determined by powder diffraction data [a = 10.0690 (8), b = 20.136 (2), c = 10.0329 (4) Å, γ = 90.01 (1)°]. A precise analysis of the BeF4 tetrahedra in the low-temperature phase shows that two independent tetrahedra rotate in opposite directions along the doubled crystallographic axis. A symmetry mode analysis of the monoclinic distortion is also reported. This is the first report of the existence of such a phase transition in K2Mn2(BeF4)3 and also of a new type of low-temperature structure for langbeinite compounds.


2007 ◽  
Vol 1056 ◽  
Author(s):  
Feiming Bai ◽  
Surendra Gupta ◽  
Archana Devasia ◽  
Santosh Kurinec ◽  
Morgan Davis ◽  
...  

ABSTRACTPhase transitions in stacked GeTe/SnTe and Ge2Se3/SnTe thin layers for potential phase-change memory applications have been investigated by X-ray diffraction using a two-dimensional area detector system. The as-deposited underlying GeTe or Ge2Se3 layer is amorphous, whereas the top SnTe layer is crystalline. In the GeTe/SnTe stack, the crystallization of GeTe phase occurs near 170°C, and upon further heating, the GeTe phase disappears, followed by the formation of rocksalt-structured GexSn1−xTe solid solution. In the Ge2Se3/SnTe stack, the phase transition starts with the separation of a SnSe phase due to the migration of Sn ions into the Ge2Se3 layer. SnSe is believed to facilitate the crystallization of Ge2Se3-SnTe solid solution at ∼360°C, which is much lower than the crystallization temperature of Ge2Se3, therefore consuming less power during the phase transition.


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