Negative thermal expansion in one-dimension of a new double sulfate AgHo(SO4)2 with isolated SO4 tetrahedra

doi:10.1016/j.jmst.2020.10.026

J. Mater. Sci. Technol. ›› 2021, Vol. 76: 111-121.DOI: 10.1016/j.jmst.2020.10.026

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Negative thermal expansion in one-dimension of a new double sulfate AgHo(SO₄)₂ with isolated SO₄ tetrahedra

Yuriy G. Denisenko^a^,^b^,^c, Victor V. Atuchin^d^,^e^,^f^,^*(), Maxim S. Molokeev^g^,^h^,ⁱ, Naizheng Wang^j, Xingxing Jiang^j, Aleksandr S. Aleksandrovsky^k^,^l, Alexander S. Krylov^m, Aleksandr S. Oreshonkov^h^,^j, Alexander E. Sedykh^b^,^h, Svetlana S. Volkova^a, Zheshuai Lin^j^,^o, Oleg V. Andreev^a^,^p, Klaus Müller-Buschbaum^b^,ⁿ

^a Institute of Chemistry, Tyumen State University, Tyumen, 625003, Russia
^b Institute of Inorganic and Analytical Chemistry, Justus-Liebig-University of Giessen, 35392, Giessen, Germany
^c Department of General and Special Chemistry, Industrial University of Tyumen, Tyumen, 625000, Russia
^d Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk, 630090, Russia
^e Laboratory of Semiconductor and Dielectric Materials, Novosibirsk State University, Novosibirsk, 630090, Russia
^f Research and Development Department, Kemerovo State University, Kemerovo, 650000, Russia
^g Laboratory of Crystal Physics, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, 660036, Russia
^h Siberian Federal University, Krasnoyarsk, 660041, Russia
ⁱ Department of Physics, Far Eastern State Transport University, Khabarovsk, 680021, Russia
^j Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
^k Laboratory of Coherent Optics, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, 660036, Russia
^l Institute of Nanotechnology, Spectroscopy and Quantum Chemistry, Siberian Federal University, Krasnoyarsk, 660041, Russia
^m Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, 660036, Russia
ⁿ Center for Materials Research (LaMa), Justus-Liebig-University Giessen, Giessen, 35392, Germany
^o University of the Chinese Academy of Sciences, Beijing, 100049, China
^p Laboratory of the Chemistry of Rare Earth Compounds, Institute of Solid State Chemistry, UB RAS, Ekaterinburg, 620137, Russia

Received:2020-06-26 Revised:2020-08-03 Accepted:2020-08-15 Published:2021-06-20 Online:2020-10-27
Contact: Victor V. Atuchin
About author:*Laboratory of Optical Materials and Structures, Insti-tute of Semiconductor Physics, SB RAS, Novosibirsk, 630090, Russia.E-mail address: atuchin@isp.nsc.ru (V.V. Atuchin).

Abstract

Abstract:

A double holmium-silver sulfate was obtained for the first time. The temperature intervals for the formation and stability of the compound were determined by differential scanning calorimetry. The crystal structure of AgHo(SO₄)₂ was determined by Rietveld method. The X-ray diffraction (XRD) analysis showed that the compound crystallizes in the monoclinic syngony, space group P2₁/m, with the unit cell parameters a = 4.71751 (4) Å, b = 6.84940 (6) Å and c = 9.89528 (9) Å, β = 95.1466 (4)°, V = 318.448 (5) Å³, Z = 2, R_B = 1.55 %, T = 303 K. Two types of sulfate tetrahedra were found in the structure, which significantly affected the spectral properties in the infrared range. In the temperature range of 143-703 K, a negative thermal expansion along the b direction accompanied by a positive thermal expansion along the a and c directions was observed. It was established that negative thermal expansion is the result of the deformation of sulfate tetrahedra, which is affected by the movement of holmium and silver atoms. The excitation in the blue spectral range (457.9 nm) produces a luminescence in light blue (489 nm), green (545 nm) and red (654 nm) spectral ranges, and the latter two were of comparable intensity that is favorable for WLED sources. The observed luminescent band distribution is ascribed to the specific crystal field at Ho³⁺ ion sites rather than a variation of radiationless probability.

Key words: Sulfate, Crystal structure, Thermal expansion, Raman, Photoluminescence, Band structure

Yuriy G. Denisenko, Victor V. Atuchin, Maxim S. Molokeev, Naizheng Wang, Xingxing Jiang, Aleksandr S. Aleksandrovsky, Alexander S. Krylov, Aleksandr S. Oreshonkov, Alexander E. Sedykh, Svetlana S. Volkova, Zheshuai Lin, Oleg V. Andreev, Klaus Müller-Buschbaum. Negative thermal expansion in one-dimension of a new double sulfate AgHo(SO₄)₂ with isolated SO₄ tetrahedra[J]. J. Mater. Sci. Technol., 2021, 76: 111-121.

Figures/Tables 16

Fig. 1. (a) Crystal structure of AgHo(SO4)2 and different Rietveld plots at (b) T = 303, (c) T = 503 and (d) T = 703 K.

Table 1 Main parameters of processing and refinement of the sample AgHo(SO4)2.

T (K)	Space group	a (Å)	b (Å)	c (Å)	β (°)	V (Å³)	Z	2θ-interval (°)	No. of reflections	No. of refined parameters	R_wp (%)	R_p (%)	R_exp (%)	χ²	R_B (%)
303	P2₁/m	4.71751 (4)	6.84940 (6)	9.89528 (9)	95.1466 (4)	318.448 (5)	2	10-144	686	61	3.29	2.51	2.06	1.59	1.55
503	P2₁/m	4.75129 (4)	6.84223 (6)	9.93141 (9)	95.0258 (4)	321.623 (5)	2	10-144	693	61	3.51	2.62	2.17	1.62	1.56
703	P2₁/m	4.80158 (6)	6.83505 (8)	9.9648 (1)	94.8957 (5)	325.841 (7)	2	10-144	700	61	3.76	2.61	2.17	1.74	2.05

Fig. 2. Cell parameter dependences on temperature: (a) a (T), (b) b (T), (c) c (T), (d) β (T) and (e) V (T).

Fig. 3. Thermal expansion tensor of AgHo(SO4)2.

Fig. 4. Structure transformations appeared upon heating. The bonds, which increase on heating, are red and, contrary, the bonds, which decrease on heating, are blue. The bond angles, which increase, decrease and are unchanged under heating are marked by red, blue and green sectors, respectively. Blue short arrows indicate the O2― ion move.

Fig. 5. SEM image of AgHo(SO4)2 particles. The fields used for EDS analysis are indicated.

Table 2 Element composition measurements by EDS.

Spectrum	Element content (wt.%)				Total
Spectrum	Ag	Ho	S	O	Total
Spectrum 1	23.22	35.49	13.78	27.51	100
Spectrum 2	23.19	35.49	13.80	27.52	100
Spectrum 3	23.20	35.50	13.78	27.52	100
Spectrum 4	23.19	35.46	13.80	27.55	100
Mean	23.20	35.49	13.79	27.52	100
Theory	23.20	35.48	13.79	27.53	100

Fig. 6. Maps of the constituent element distribution in the powder sample of AgHo(SO4)2.

Fig. 7. TG/DSC curves recorded for the mixture of sulfates Ag2SO4 and Ho2(SO4)3.

Fig. 8. Panoramic infrared and Raman spectra of AgHo(SO4)2.

Table 3 Correlation diagram between Td point symmetry, Cs sites symmetry and C2h factor group symmetry for SO4 tetrahedra.

Wavenumber (cm^-1) [53]	T_d Point group	C_s Site symmetry	C_2h Factor group symmetry
983	A₁ (ν₁)	A’	A_g+B_u
450	E (ν₂)	A’+A’’	A_g+B_u+B_g+A_u
1105	F₂ (ν₃)	2A’+A’’	2A_g+2B_u+B_g+A_u
611	F₂ (ν₄)	2A’+A’’	2A_g+2B_u+B_g+A_u

Table 4 Calculated (Raman) wavenumbers versus experimental Raman and IR data.

Raman		Infrared	Assignment
exp. (cm^-1)	calc. (cm^-1)	exp. (cm^-1)
1162	1168	1269
1131	1120	1161	ν₃ SO₄
1089	1089	1111
1061		1049
1012	1004	1016	ν₁ SO₄
997		995	ν₁ SO₄
692	699	687
662	674	663
620	631	601	ν₄ SO₄
606	605
603	576
594		589
515	539	532
471	497	489	ν₂ SO₄
411	386
406	372
	352
252	299
232	226		rot. SO₄
209
154
132
113
105
65
54
32

Fig. 9. Visible wavelength range of high resolution luminescence spectra of AgHo(SO4)2 (red, excited at 457.9 nm) and of reference crystals Rb2KHoF6 (blue, excited at 355 nm) and HoAl3(BO3)4 (black, excited at 457.9 nm).

Fig. 10. AgHo(SO4)2 band structure: (a) for the spin up and (b) for the spin down.

Fig. 11. Density of states of AgHo(SO4)2.

Fig. 12. AgHo(SO4)2 phonon DOS.

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Negative thermal expansion in one-dimension of a new double sulfate AgHo(SO₄)₂ with isolated SO₄ tetrahedra

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