Influence of microstructure on symmetry determination of piezoceramics

Hinterstein, M.; Mgbemere, H.E.; Hoelzel, M.; Rheinheimer, W.; Adabifiroozjaei, E.; Koshy, P.; Sorrell, C.C.; Hoffman, M.

doi:10.1107/S1600576718003916

Influence of microstructure on symmetry determination of piezoceramics

M. Hinterstein, H. E. Mgbemere, M. Hoelzel, W. Rheinheimer, E. Adabifiroozjaei, P. Koshy, C. C. Sorrell and M. Hoffman

The origin of the complex reflection splitting in potassium sodium niobate doped with lithium and manganese was investigated using temperature-dependent high-resolution X-ray and neutron diffraction as well as electron probe microanalysis and scanning electron microscopy. Two structural models were developed from the diffraction data. A single-phase monoclinic Pm model is known from the literature and is able to reproduce the diffraction patterns perfectly. However, a model with phase coexistence of two classical orthorhombic Amm2 phases can also reproduce the diffraction data with equal accuracy. Scanning electron microscopy in combination with electron probe microanalysis revealed segregation of the A-site substituents potassium and sodium. This favours the model with phase coexistence and confirms the need for comprehensive analyses with complementary methods to cover a broad range of length scales as well as to assess both average and local structure.

Keywords: piezoceramics; X-ray diffraction; neutron diffraction; potassium sodium niobate; microstructure.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600576718003916/aj5301sup1.cif Contains datablocks global, orthorhombic_1_ND, orthorhombic_2_ND, orthorhombic_1_XRD, orthorhombic_2_XRD, monoclinic_ND, monoclinic_XRD, tetragonal_1_ND, tetragonal_2_ND, cubic_1_ND, cubic_2_ND
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301monoclinic_NDsup2.hkl Contains datablock monoclinic_ND
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301monoclinic_NDsup3.rtv Contains datablock monoclinic_ND
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301monoclinic_XRDsup4.hkl Contains datablock monoclinic_XRD
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301monoclinic_XRDsup5.rtv Contains datablock monoclinic_XRD
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301orthorhombic_1_NDsup6.hkl Contains datablock orthorhombic_1_ND
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301orthorhombic_1_NDsup7.rtv Contains datablock orthorhombic_1_ND
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301orthorhombic_1_XRDsup8.hkl Contains datablock orthorhombic_1_XRD
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301orthorhombic_1_XRDsup9.rtv Contains datablock orthorhombic_1_XRD
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301orthorhombic_2_NDsup10.hkl Contains datablock orthorhombic_2_ND
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301orthorhombic_2_NDsup11.rtv Contains datablock orthorhombic_2_ND
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301orthorhombic_2_XRDsup12.hkl Contains datablock orthorhombic_2_XRD
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301orthorhombic_2_XRDsup13.rtv Contains datablock orthorhombic_2_XRD
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301tetragonal_1_NDsup14.hkl Contains datablock tetragonal_1_ND
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301tetragonal_1_NDsup15.rtv Contains datablock tetragonal_1_ND
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301tetragonal_2_NDsup16.hkl Contains datablock tetragonal_2_ND
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301tetragonal_2_NDsup17.rtv Contains datablock tetragonal_2_ND
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301cubic_1_NDsup18.hkl Contains datablock cubic_1_ND
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301cubic_1_NDsup19.rtv Contains datablock cubic_1_ND
	Structure factor file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301cubic_2_NDsup20.hkl Contains datablock cubic_2_ND
	Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600576718003916/aj5301cubic_2_NDsup21.rtv Contains datablock cubic_2_ND

CCDC references: 1828074; 1828075; 1828076; 1828077; 1828078; 1828079; 1828080; 1828081; 1828082; 1828083

Computing details top

For all structures, program(s) used to refine structure: FULLPROF.

(orthorhombic_1_ND) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	c = 5.6426 (2) Å
M_r = 170.23	V = 125.50 (1) Å³
Orthorhombic, Amm2	Z = 2
Hall symbol: A 2 -2	Neutron radiation
a = 3.94590 (5) Å	T = 300 K
b = 5.6366 (2) Å	grey

Data collection top

Powder diffractometer	2θ_min = 1.216°, 2θ_max = 151.866°, 2θ_step = 0.050°
Radiation source: nuclear reactor, FRMII/SPODI

Refinement top

R_p = 0.033	3014 data points
R_wp = 0.043	66 parameters
R_exp = 0.016	0 restraints
R_Bragg = 0.023

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.50000	0.25000	0.248 (3)	0.0088 (5)*
O2	0.00000	0.00000	0.523 (2)	0.0028 (8)*
Na1	0.00000	0.00000	0.00000	0.0120 (9)*	0.48000
K1	0.00000	0.00000	0.00000	0.0120 (9)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0120 (9)*	0.04000
Nb1	0.50000	0.00000	0.489 (2)	0.0035 (4)*	0.98000
Mn1	0.50000	0.00000	0.489 (2)	0.0035 (4)*	0.02000

(orthorhombic_2_ND) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	c = 5.67416 (10) Å
M_r = 170.23	V = 126.73 (1) Å³
Orthorhombic, Amm2	Z = 2
Hall symbol: A 2 -2	Neutron radiation
a = 3.94200 (5) Å	T = 300 K
b = 5.66580 (15) Å	grey

Data collection top

Powder diffractometer	2θ_min = 1.216°, 2θ_max = 151.866°, 2θ_step = 0.050°
Radiation source: nuclear reactor, FRMII/SPODI

Refinement top

R_p = 0.033	3014 data points
R_wp = 0.043	66 parameters
R_exp = 0.016	0 restraints
R_Bragg = 0.022

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.50000	0.25000	0.2755 (18)	0.0156 (8)*
O2	0.00000	0.00000	0.5344 (15)	0.0067 (9)*
Na1	0.00000	0.00000	0.00000	0.0122 (9)*	0.48000
K1	0.00000	0.00000	0.00000	0.0122 (9)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0122 (9)*	0.04000
Nb1	0.50000	0.00000	0.4832 (15)	−0.0022 (4)*	0.98000
Mn1	0.50000	0.00000	0.4832 (15)	−0.0022 (4)*	0.02000

(orthorhombic_1_XRD) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	c = 5.6426 (2) Å
M_r = 170.23	V = 125.50 (1) Å³
Orthorhombic, Amm2	Z = 2
Hall symbol: A 2 -2	Synchrotron radiation
a = 3.94590 (5) Å	T = 300 K
b = 5.6366 (2) Å	grey

Data collection top

Powder diffractometer	2θ_min = 9.000°, 2θ_max = 49.492°, 2θ_step = 0.002°
Radiation source: synchrotron, DESY/B2

Refinement top

R_p = 0.122	20245 data points
R_wp = 0.163	66 parameters
R_exp = 0.115	0 restraints
R_Bragg = 0.074

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.50000	0.25000	0.248 (3)	0.0088 (5)*
O2	0.00000	0.00000	0.523 (2)	0.0028 (8)*
Na1	0.00000	0.00000	0.00000	0.0120 (9)*	0.48000
K1	0.00000	0.00000	0.00000	0.0120 (9)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0120 (9)*	0.04000
Nb1	0.50000	0.00000	0.489 (2)	0.0035 (4)*	0.98000
Mn1	0.50000	0.00000	0.489 (2)	0.0035 (4)*	0.02000

(orthorhombic_2_XRD) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	c = 5.67416 (10) Å
M_r = 170.23	V = 126.73 (1) Å³
Orthorhombic, Amm2	Z = 2
Hall symbol: A 2 -2	Synchrotron radiation
a = 3.94200 (5) Å	T = 300 K
b = 5.66580 (15) Å	grey

Data collection top

Powder diffractometer	2θ_min = 9.000°, 2θ_max = 49.492°, 2θ_step = 0.002°
Radiation source: synchrotron, DESY/B2

Refinement top

R_p = 0.122	20245 data points
R_wp = 0.163	66 parameters
R_exp = 0.115	0 restraints
R_Bragg = 0.071

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.50000	0.25000	0.2755 (18)	0.0156 (8)*
O2	0.00000	0.00000	0.5344 (15)	0.0067 (9)*
Na1	0.00000	0.00000	0.00000	0.0122 (9)*	0.48000
K1	0.00000	0.00000	0.00000	0.0122 (9)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0122 (9)*	0.04000
Nb1	0.50000	0.00000	0.4832 (15)	−0.0022 (4)*	0.98000
Mn1	0.50000	0.00000	0.4832 (15)	−0.0022 (4)*	0.02000

(monoclinic_ND) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	β = 90°
M_r = 170.23	V = 63.07 (1) Å³
Monoclinic, P11m	Z = 1
Hall symbol: P -2	Neutron radiation
a = 4.01035 (5) Å	T = 300 K
b = 3.98782 (5) Å	grey
c = 3.94398 (4) Å

Data collection top

Powder diffractometer	2θ_min = 1.213°, 2θ_max = 151.863°, 2θ_step = 0.050°
Radiation source: nuclear reactor, FRMII/SPODI

Refinement top

R_p = 0.034	3014 data points
R_wp = 0.044	69 parameters
R_exp = 0.016	0 restraints
R_Bragg = 0.027

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.540 (2)	0.525 (3)	0.00000	0.00841 (16)*
O2	0.5471 (15)	0.014 (3)	0.50000	0.00841 (16)*
O3	0.0407 (17)	0.520 (2)	0.50000	0.00841 (16)*
Na1	0.00000	0.00000	0.00000	0.0138 (4)*	0.48000
K1	0.00000	0.00000	0.00000	0.0138 (4)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0138 (4)*	0.04000
Nb1	0.5021 (16)	0.489 (2)	0.50000	0.00072 (18)*	0.98000
Mn1	0.5021 (16)	0.489 (2)	0.50000	0.00072 (18)*	0.02000

(monoclinic_XRD) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	β = 90°
M_r = 170.23	V = 63.07 (1) Å³
Monoclinic, P11m	Z = 1
Hall symbol: P -2	Synchrotron radiation
a = 4.01035 (5) Å	T = 300 K
b = 3.98782 (5) Å	grey
c = 3.94398 (4) Å

Data collection top

Powder diffractometer	2θ_min = 8.999°, 2θ_max = 49.491°, 2θ_step = 0.002°
Radiation source: synchrotron, DESY/B2

Refinement top

R_p = 0.111	20245 data points
R_wp = 0.152	69 parameters
R_exp = 0.115	0 restraints
R_Bragg = 0.072

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.540 (2)	0.525 (3)	0.00000	0.00841 (16)*
O2	0.5471 (15)	0.014 (3)	0.50000	0.00841 (16)*
O3	0.0407 (17)	0.520 (2)	0.50000	0.00841 (16)*
Na1	0.00000	0.00000	0.00000	0.0138 (4)*	0.48000
K1	0.00000	0.00000	0.00000	0.0138 (4)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0138 (4)*	0.04000
Nb1	0.5021 (16)	0.489 (2)	0.50000	0.00072 (18)*	0.98000
Mn1	0.5021 (16)	0.489 (2)	0.50000	0.00072 (18)*	0.02000

(tetragonal_1_ND) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	V = 63.37 (1) Å³
M_r = 170.23	Z = 1
Tetragonal, P4mm	Neutron radiation
Hall symbol: P 4 -2	T = 526 K
a = 3.96592 (8) Å	grey
c = 4.02904 (7) Å

Data collection top

Powder diffractometer	2θ_min = 0.941°, 2θ_max = 151.891°, 2θ_step = 0.050°
Radiation source: nuclear reactor, FRMII/SPODI

Refinement top

R_p = 0.036	3014 data points
R_wp = 0.056	41 parameters
R_exp = 0.016	0 restraints
R_Bragg = 0.037

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.50000	0.00000	0.520 (2)	0.0100 (6)*
O2	0.50000	0.50000	0.010 (3)	0.0152 (7)*
Na1	0.00000	0.00000	0.00000	0.0168 (9)*	0.48000
K1	0.00000	0.00000	0.00000	0.0168 (9)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0168 (9)*	0.04000
Nb1	0.50000	0.50000	0.478 (2)	0.0008 (6)*	0.98000
Mn1	0.50000	0.50000	0.478 (2)	0.0008 (6)*	0.01000

(tetragonal_2_ND) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	V = 63.01 (1) Å³
M_r = 170.23	Z = 1
Tetragonal, P4mm	Neutron radiation
Hall symbol: P 4 -2	T = 526 K
a = 3.95807 (10) Å	grey
c = 4.0220 (2) Å

Data collection top

Powder diffractometer	2θ_min = 0.941°, 2θ_max = 151.891°, 2θ_step = 0.050°
Radiation source: nuclear reactor, FRMII/SPODI

Refinement top

R_p = 0.036	3014 data points
R_wp = 0.056	41 parameters
R_exp = 0.016	0 restraints
R_Bragg = 0.038

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.50000	0.00000	0.565 (4)	0.0195 (12)*
O2	0.50000	0.50000	0.066 (4)	0.0214 (14)*
Na1	0.00000	0.00000	0.00000	0.030 (2)*	0.48000
K1	0.00000	0.00000	0.00000	0.030 (2)*	0.48000
Li1	0.00000	0.00000	0.00000	0.030 (2)*	0.04000
Nb1	0.50000	0.50000	0.525 (3)	0.0131 (12)*	0.98000
Mn1	0.50000	0.50000	0.525 (3)	0.0131 (12)*	0.01000

(cubic_1_ND) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	V = 63.52 (1) Å³
M_r = 170.23	Z = 1
Cubic, Pm3m	Neutron radiation
Hall symbol: -P 4 2 3	T = 776 K
a = 3.99001 (5) Å	grey

Data collection top

Powder diffractometer	2θ_min = 1.241°, 2θ_max = 151.891°, 2θ_step = 0.050°
Radiation source: nuclear reactor, FRMII/SPODI

Refinement top

R_p = 0.038	3014 data points
R_wp = 0.064	26 parameters
R_exp = 0.016	0 restraints
R_Bragg = 0.043

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.50000	0.00000	0.50000	0.0132 (7)*
Na1	0.00000	0.00000	0.00000	0.0257 (10)*	0.48000
K1	0.00000	0.00000	0.00000	0.0257 (10)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0257 (10)*	0.03984
Nb1	0.50000	0.50000	0.50000	0.0043 (7)*	0.98016
Mn1	0.50000	0.50000	0.50000	0.0043 (7)*	0.01008

(cubic_2_ND) top

Crystal data top

K0.48Na0.48Li0.04Nb0.98Mn0.02O₃	V = 63.21 (1) Å³
M_r = 170.23	Z = 1
Cubic, Pm3m	Neutron radiation
Hall symbol: -P 4 2 3	T = 776 K
a = 3.98346 (7) Å	grey

Data collection top

Powder diffractometer	2θ_min = 1.241°, 2θ_max = 151.891°, 2θ_step = 0.050°
Radiation source: nuclear reactor, FRMII/SPODI

Refinement top

R_p = 0.038	3014 data points
R_wp = 0.064	26 parameters
R_exp = 0.016	0 restraints
R_Bragg = 0.043

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.50000	0.00000	0.50000	0.0250 (7)*
Na1	0.00000	0.00000	0.00000	0.0377 (11)*	0.48000
K1	0.00000	0.00000	0.00000	0.0377 (11)*	0.48000
Li1	0.00000	0.00000	0.00000	0.0377 (11)*	0.03984
Nb1	0.50000	0.50000	0.50000	0.0142 (7)*	0.98016
Mn1	0.50000	0.50000	0.50000	0.0142 (7)*	0.01008

Format		BIBTeX
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Format		BIBTeX
		EndNote
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		Refer
		Medline
		CIF
		SGML
		Text
		Plain Text

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