Growth, structural and thermophysical properties of TbNbO4 crystals

CrystEngComm ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 1455-1462 ◽  
Author(s):  
Jiayi Guo ◽  
Junyu Ren ◽  
Rui Cheng ◽  
Qing Dong ◽  
Cunyuan Gao ◽  
...  

An as-grown TbNbO4 crystal has a negative thermal expansion and the zero thermal expansion could be achieved.

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5021
Author(s):  
Philipp Keuter ◽  
Anna L. Ravensburg ◽  
Marcus Hans ◽  
Soheil Karimi Aghda ◽  
Damian M. Holzapfel ◽  
...  

The HfV2–HfV2O7 composite is proposed as a material with potentially temperature-independent thermophysical properties due to the combination of anomalously increasing thermoelastic constants of HfV2 with the negative thermal expansion of HfV2O7. Based on literature data, the coexistence of both a near-zero temperature coefficient of elasticity and a coefficient of thermal expansion is suggested for a composite with a phase fraction of approximately 30 vol.% HfV2 and 70 vol.% HfV2O7. To produce HfV2–HfV2O7 composites, two synthesis pathways were investigated: (1) annealing of sputtered HfV2 films in air to form HfV2O7 oxide on the surface and (2) sputtering of HfV2O7/HfV2 bilayers. The high oxygen mobility in HfV2 is suggested to inhibit the formation of crystalline HfV2–HfV2O7 composites by annealing HfV2 in air due to oxygen-incorporation-induced amorphization of HfV2. Reducing the formation temperature of crystalline HfV2O7 from 550 °C, as obtained upon annealing, to 300 °C using reactive sputtering enables the synthesis of crystalline bilayered HfV2–HfV2O7.


2021 ◽  
Vol 33 (4) ◽  
pp. 1498-1505
Author(s):  
Takumi Nishikubo ◽  
Takahiro Ogata ◽  
Lalitha Kodumudi Venkataraman ◽  
Daniel Isaia ◽  
Zhao Pan ◽  
...  

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yongqiang Qiao ◽  
Yuzhu Song ◽  
Andrea Sanson ◽  
Longlong Fan ◽  
Qiang Sun ◽  
...  

AbstractNegative thermal expansion (NTE) is an intriguing property, which is generally triggered by a single NTE mechanism. In this work, an enhanced NTE (αv = −32.9 × 10−6 K−1, ΔT = 175 K) is achieved in YbMn2Ge2 intermetallic compound to be caused by a dual effect of magnetism and valence transition. In YbMn2Ge2, the Mn sublattice that forms the antiferromagnetic structure induces the magnetovolume effect, which contributes to the NTE below the Néel temperature (525 K). Concomitantly, the valence state of Yb increases from 2.40 to 2.82 in the temperature range of 300–700 K, which simultaneously causes the contraction of the unit cell volume due to smaller volume of Yb3+ than that of Yb2+. As a result, such combined effect gives rise to an enhanced NTE. The present study not only sheds light on the peculiar NTE mechanism of YbMn2Ge2, but also indicates the dual effect as a possible promising method to produce enhanced NTE materials.


Author(s):  
Hyeong Jin Kim ◽  
Wenjie Wang ◽  
Surya Mallapragada ◽  
Alex Travesset ◽  
David Vaknin

2021 ◽  
Vol 103 (9) ◽  
Author(s):  
J. L. Niedziela ◽  
L. D. Sanjeewa ◽  
A. A. Podlesnyak ◽  
L. DeBeer-Schmitt ◽  
S. J. Kuhn ◽  
...  

2021 ◽  
Author(s):  
Peng Du ◽  
Laihui Luo ◽  
Yafei Hou ◽  
Weiping Li

Rational control of thermal quenching performance is crucial for achieving high quality luminescent thermometer. Herein, we report the Tb3+/Yb3+-coactivated Y2Mo3O12 (YMO) negative thermal expansion (NTE) microparticles with color-tunable emissions. Irradiated...


Sign in / Sign up

Export Citation Format

Share Document