<abstract xmlns="http://www.w3.org/1999/xhtml"><p>In this article, we have investigated a fitting proposal model for calculating the crystallite size of pure NiO thin films by varying the structural parameters, such as full width at half-maximum <italic>β</italic>, lattice parameter <italic>a</italic> and differences in <italic>a</italic> − <italic>a</italic><sub>0</sub>. The experimental data of NiO thin films were prepared at several deposition temperatures in the range of 380–460°C. All estimated values of crystallite sizes are proportional to the experimental data. Thus, the measurement of the crystallite size values by this proposed model is compatible with practical measurements qualitative.</p></abstract>

In this article, we have investigated a fitting proposal model for calculating the crystallite size of pure NiO thin films by varying the structural parameters, such as full width at half-maximum β, lattice parameter a and differences in a − a0. The experimental data of NiO thin films were prepared at several deposition temperatures in the range of 380–460°C. All estimated values of crystallite sizes are proportional to the experimental data. Thus, the measurement of the crystallite size values by this proposed model is compatible with practical measurements qualitative.


<div xmlns="http://www.w3.org/1999/xhtml"><sec id="j_rmzmag-2020-0001_s_001_w2aab3b7b9b1b6b1ab1aAa"><div>Introduction</div><p>In previous years, the investigation of new materials for photovoltaic applications was dependent and related to the experimental and modelling parameters of any properties. Nickel oxide was obtained to belong in the group of semiconductor materials and is one of the best materials at present because of its good properties [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_001_w2aab3b7b9b1b6b1ab2ab1Aa">1</a>].</p><p>Nickel oxide (NiO) is a semiconductor material with a nature of p-type, which belonged to the part of TCO family. This attribute of NiO has several potential applications, for example, it is used in the gas sensors due to its band gap energy in the range of 3.6−4.0 eV and for the organic solar cells applications due to its p-type semiconducting [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_002_w2aab3b7b9b1b6b1ab2ab2Aa">2</a>]. It can be used in transparent diodes and even in the transparent transistors caused by the best optical transmission and electrical conductivity. Moreover, NiO can be used for defrosting windows due to its good conductivity, and fabricated NiO can be used in the UV photodetectors and touch screens due to its good responsivity [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_003_w2aab3b7b9b1b6b1ab2ab3Aa">3</a>, <a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_004_w2aab3b7b9b1b6b1ab2ab4Aa">4</a>].</p><p>In the present article, we have studied and investigated a relationship to calculate the crystallite size (<italic>G</italic>) from the measured structural parameters of the X-ray diffraction in the NiO thin films. We have used the experimental data of NiO thin films prepared at several deposition temperatures in the range of 380–460°C [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_005_w2aab3b7b9b1b6b1ab2ab5Aa">5</a>], which present the following parameters, such as the diffraction angle 2<italic>θ</italic>, the full width at half-maximum (FWHM), the crystallite size <italic>G</italic>, the lattice parameter <italic>a</italic> and <italic>a</italic> − <italic>a</italic><sub>0</sub> of (111) diffraction peak for NiO thin films at several deposition temperatures.</p></sec><sec id="j_rmzmag-2020-0001_s_002_w2aab3b7b9b1b6b1ab1b1Aa"><div>Materials and Methods</div><p>The NiO samples were fabricated on the glass substrates using a pneumatic spray technique with 0.1 M of the precursor molarity. The NiO thin films were deposited at several deposition temperatures in the range of 380–460°C [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_005_w2aab3b7b9b1b6b1ab2ab5Aa">5</a>] (see <a ref-type="table" href="#j_rmzmag-2020-0001_tab_001_w2aab3b7b9b1b6b1ab1b1b2Aa">Table 1</a>).</p><table-wrap id="j_rmzmag-2020-0001_tab_001_w2aab3b7b9b1b6b1ab1b1b2Aa" position="float"><label>Table 1</label><caption><p>The diffraction angle 2θ, the full width at half-maximum (FWHM), the crystallite size G, the lattice parameter a and a − a<sub>0</sub> of (111) diffraction peak for NiO thin films at several deposition temperatures [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_005_w2aab3b7b9b1b6b1ab2ab5Aa">5</a>].</p></caption><table rules="rows"><thead><tr><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold>Deposition temperature Ts (°C)</bold></th><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold>2<italic>θ</italic> (deg)</bold></th><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold><italic>β</italic> (rad)</bold></th><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold><italic>G</italic> (nm)</bold></th><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold><italic>a</italic> (nm)</bold></th><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold><italic>a</italic> − <italic>a</italic><sub>0</sub> (nm)</bold></th></tr></thead><tbody><tr><td align="center" valign="top">380</td><td align="center" valign="top">37.80</td><td align="center" valign="top">0.00766</td><td align="center" valign="top">19.13</td><td align="center" valign="top">0.4122281</td><td align="center" valign="top">0.00537184</td></tr><tr><td align="center" valign="top">400</td><td align="center" valign="top">37.67</td><td align="center" valign="top">0.00781</td><td align="center" valign="top">18.74</td><td align="center" valign="top">0.4135872</td><td align="center" valign="top">0.00401271</td></tr><tr><td align="center" valign="top">420</td><td align="center" valign="top">37.64</td><td align="center" valign="top">0.00868</td><td align="center" valign="top">16.88</td><td align="center" valign="top">0.4138530</td><td align="center" valign="top">0.00374695</td></tr><tr><td align="center" valign="top">440</td><td align="center" valign="top">37.60</td><td align="center" valign="top">0.00799</td><td align="center" valign="top">18.31</td><td align="center" valign="top">0.4143484</td><td align="center" valign="top">0.00325152</td></tr><tr><td align="center" valign="top">460</td><td align="center" valign="top">37.66</td><td align="center" valign="top">0.00707</td><td align="center" valign="top">20.72</td><td align="center" valign="top">0.4136507</td><td align="center" valign="top">0.00394921</td></tr></tbody></table></table-wrap><p><a ref-type="table" href="#j_rmzmag-2020-0001_tab_001_w2aab3b7b9b1b6b1ab1b1b2Aa">Table 1</a> presents that the NiO thin films were nanocrystalline and had a cubic structure with (111) crystal plane at the higher intensity, which has preferential a-axis orientation along with (111) crystal plane.</p><p>The Miller indices (<italic>hkl</italic>) were obtained from the Bragg equation [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_006_w2aab3b7b9b1b6b1ab2ab6Aa">6</a>]:
<disp-formula id="j_rmzmag-2020-0001_eq_001_w2aab3b7b9b1b6b1ab1b1b4b5Aa"><label>(1)</label><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_rmzmag-2020-0001_eq_001.png"></graphic><math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>n</mi><mo>λ</mo><mo>=</mo><mn>2</mn><msub><mi>d</mi><mrow><mi mathvariant="italic">hkl</mi></mrow></msub><mo> </mo><mi mathvariant="italic">sin</mi><mo> </mo><mo>θ</mo></mrow></math><tex-math>n\lambda = 2{d_{hkl}}\,sin\,\theta</tex-math></alternatives></disp-formula>
where <italic>n</italic>, <italic>λ</italic>, <italic>d<sub>hkl</sub></italic> and <italic>θ</italic> are the integers called the order of diffraction, the wavelength longer of X-ray (<italic>λ</italic> = 1.5406 A°), the interplanar spacing and the diffraction angle, respectively.</p><p>The lattice parameter <italic>a</italic> of cubic structure for NiO thin films was determined in <a ref-type="disp-formula" href="#j_rmzmag-2020-0001_eq_001_w2aab3b7b9b1b6b1ab1b1b4b5Aa">Eq. (1)</a> and XRD patterns using the following formula [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_005_w2aab3b7b9b1b6b1ab2ab5Aa">5</a>]:
<disp-formula id="j_rmzmag-2020-0001_eq_002_w2aab3b7b9b1b6b1ab1b1b5b7Aa"><label>(2)</label><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_rmzmag-2020-0001_eq_002.png"></graphic><math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="block"><mrow><msub><mi>d</mi><mrow><mi>h</mi><mo> </mo><mi>k</mi><mo> </mo><mi>l</mi></mrow></msub><mo>=</mo><mfrac><mi>a</mi><mrow><msqrt><mrow><mi>h</mi><mo>+</mo><mi>k</mi><mo>+</mo><mi>l</mi></mrow></msqrt></mrow></mfrac></mrow></math><tex-math>{d_{h\,k\,l}} = {a \over {\sqrt {h + k + l}}}</tex-math></alternatives></disp-formula></p><p>The differences <italic>a</italic> − <italic>a</italic><sub>0</sub> of (111) crystal plane are given by the following relation [6]:
<disp-formula id="j_rmzmag-2020-0001_eq_003_w2aab3b7b9b1b6b1ab1b1b6b6Aa"><label>(3)</label><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_rmzmag-2020-0001_eq_003.png"></graphic><math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>a</mi><mo>−</mo><msub><mi>a</mi><mn>0</mn></msub><mo>=</mo><msub><mi>d</mi><mrow><mi mathvariant="italic">hkl</mi></mrow></msub><msqrt><mrow><mi>h</mi><mo>+</mo><mi>k</mi><mo>+</mo><mi>l</mi></mrow></msqrt></mrow></math><tex-math>a - {a_0} = {d_{hkl}}\sqrt {h + k + l}</tex-math></alternatives></disp-formula>
where <italic>a</italic><sub>0</sub> is the standard lattice parameter of NiO (standard <italic>a</italic><sub>0</sub> = 0.4176 nm). The crystallite size of (111) crystal plane for the fabricated NiO thin films was calculated from the Scherer's formula [<a ref-type="bibr" href="#j_rmzmag-2020-0001_ref_007_w2aab3b7b9b1b6b1ab2ab7Aa">7</a>]:
<disp-formula id="j_rmzmag-2020-0001_eq_004_w2aab3b7b9b1b6b1ab1b1b6c16Aa"><label>(4)</label><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_rmzmag-2020-0001_eq_004.png"></graphic><math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>G</mi><mo>=</mo><mfrac><mrow><mn>0</mn><mo>.</mo><mn>9</mn><mo>λ</mo></mrow><mrow><mo>β</mo><mo> </mo><mi mathvariant="italic">cos</mi><mo> </mo><mo>θ</mo></mrow></mfrac></mrow></math><tex-math>G = {{0.9\lambda} \over {\beta \,cos\,\theta}}</tex-math></alternatives></disp-formula>
where <italic>G</italic> is the experiment crystallite size, <italic>β</italic> is the FWHM and <italic>θ</italic> is the diffraction angle peak (see <a ref-type="table" href="#j_rmzmag-2020-0001_tab_001_w2aab3b7b9b1b6b1ab1b1b2Aa">Table 1</a>).</p></sec><sec id="j_rmzmag-2020-0001_s_003_w2aab3b7b9b1b6b1ab1b2Aa"><div>Results and Discussion</div><p>In this article, we have estimated the crystallite size (<italic>G</italic>) by fitting relationships between the structural parameters (<italic>β</italic>, <italic>a</italic> and <italic>a</italic> − <italic>a</italic><sub>0</sub>), which is detected in the following empirical relationship:
<disp-formula id="j_rmzmag-2020-0001_eq_005_w2aab3b7b9b1b6b1ab1b2b1c12Aa"><label>(5)</label><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_rmzmag-2020-0001_eq_005.png"></graphic><math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="block"><mrow><mi>G</mi><mo>=</mo><msub><mi>C</mi><mn>1</mn></msub><mfrac><mi>a</mi><mo>β</mo></mfrac><mo>−</mo><msub><mi>C</mi><mn>2</mn></msub><mfrac><mrow><mi>a</mi><mo>−</mo><msub><mi>a</mi><mn>0</mn></msub></mrow><mo>β</mo></mfrac></mrow></math><tex-math>G = {C_1}{a \over \beta} - {C_2}{{a - {a_0}} \over \beta}</tex-math></alternatives></disp-formula>
where <italic>C</italic><sub>1</sub> and <italic>C</italic><sub>2</sub> are constants as <italic>C</italic><sub>1</sub> = 0.365 and <italic>C</italic><sub>2</sub> = 0.02. The results of this fitting are given in <a ref-type="table" href="#j_rmzmag-2020-0001_tab_002_w2aab3b7b9b1b6b1ab1b2b2Aa">Table 2</a>.</p><table-wrap id="j_rmzmag-2020-0001_tab_002_w2aab3b7b9b1b6b1ab1b2b2Aa" position="float"><label>Table 2</label><caption><p>The crystallite size G experimental and correlated at several deposition temperatures.</p></caption><table rules="rows"><thead><tr><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold>Deposition temperature Ts (°C)</bold></th><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold>Experimental crystallite size (nm)</bold></th><th align="center" valign="middle" style="background-color: #F1F1F2;"><bold>Fitting crystallite size (nm)</bold></th></tr></thead><tbody><tr><td align="center" valign="top">380</td><td align="center" valign="top">19.13</td><td align="center" valign="top">19.14</td></tr><tr><td align="center" valign="top">400</td><td align="center" valign="top">18.74</td><td align="center" valign="top">18.84</td></tr><tr><td align="center" valign="top">420</td><td align="center" valign="top">16.88</td><td align="center" valign="top">16.96</td></tr><tr><td align="center" valign="top">440</td><td align="center" valign="top">18.31</td><td align="center" valign="top">18.45</td></tr><tr><td align="center" valign="top">460</td><td align="center" valign="top">20.72</td><td align="center" valign="top">20.82</td></tr></tbody></table></table-wrap><p><a ref-type="fig" href="#j_rmzmag-2020-0001_fig_001_w2aab3b7b9b1b6b1ab1b2b4Aa">Figure 1</a> shows the variation of the experimental and fitting of the crystallite size at several deposition temperatures in the range of 380–460°C. The measured values of the crystallite sizes were obtained using <a ref-type="disp-formula" href="#j_rmzmag-2020-0001_eq_005_w2aab3b7b9b1b6b1ab1b2b1c12Aa">Eq. (5)</a>, which were given in <a ref-type="table" href="#j_rmzmag-2020-0001_tab_002_w2aab3b7b9b1b6b1ab1b2b2Aa">Table 2</a>. This correlation indicated that the crystallite sizes of the NiO thin films can be predominantly influenced by the FWHM <italic>β</italic>, the lattice parameter <italic>a</italic> and the differences in <italic>a</italic> − <italic>a</italic><sub>0</sub> of the NiO thin films. As seen, all estimated values of crystallite sizes are proportional to the experimental data. Thus, the measurement of the crystallite size values by this proposed model is compatible with practical measurements qualitative. This attribution can be observed with the variation of FWHM <italic>β</italic> (see <a ref-type="fig" href="#j_rmzmag-2020-0001_fig_002_w2aab3b7b9b1b6b1ab1b2b5Aa">Figure 2</a>). This observation was investigated to demonstrate that the calculation of the crystallite size can be influenced by the measurements of the structural parameters (<italic>β</italic>, <italic>a</italic> and <italic>a</italic> − <italic>a</italic><sub>0</sub>).</p><figure id="j_rmzmag-2020-0001_fig_001_w2aab3b7b9b1b6b1ab1b2b4Aa" position="float" fig-type="figure"><h2>Figure 1</h2><figCaption><p>The variation of the crystallite size G experimental and fitting at several deposition temperatures.</p></figCaption><img xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_rmzmag-2020-0001_fig_001.jpg" src="https://sciendo-parsed.s3.eu-central-1.amazonaws.com/647369a44e662f30ba53d208/j_rmzmag-2020-0001_fig_001.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&amp;X-Amz-Date=20240520T202109Z&amp;X-Amz-SignedHeaders=host&amp;X-Amz-Expires=18000&amp;X-Amz-Credential=AKIA6AP2G7AKP25APDM2%2F20240520%2Feu-central-1%2Fs3%2Faws4_request&amp;X-Amz-Signature=f21f5ffd30069d14e5e377ada1101f29bd16e2d7cc8663d4b061f615d3be0583" class="mw-100"/></figure><figure id="j_rmzmag-2020-0001_fig_002_w2aab3b7b9b1b6b1ab1b2b5Aa" position="float" fig-type="figure"><h2>Figure 2</h2><figCaption><p>The variation of the crystallite size G experimental and fitting at several FWHM values.</p></figCaption><img xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_rmzmag-2020-0001_fig_002.jpg" src="https://sciendo-parsed.s3.eu-central-1.amazonaws.com/647369a44e662f30ba53d208/j_rmzmag-2020-0001_fig_002.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&amp;X-Amz-Date=20240520T202109Z&amp;X-Amz-SignedHeaders=host&amp;X-Amz-Expires=18000&amp;X-Amz-Credential=AKIA6AP2G7AKP25APDM2%2F20240520%2Feu-central-1%2Fs3%2Faws4_request&amp;X-Amz-Signature=56e8b94439fd0fba9f2993e2e60a8f540d1b66db8bf9e14c1ffca14d63990827" class="mw-100"/></figure></sec><sec id="j_rmzmag-2020-0001_s_004_w2aab3b7b9b1b6b1ab1b3Aa"><div>Conclusions</div><p>In this article, the direct correlation of the crystallite size from the experimental values was investigated by a fitting model wherein the calculated crystallite size of the pure NiO thin films was detected in the structural parameters, such as the FWHM <italic>β</italic>, the lattice parameter <italic>a</italic> and the differences in <italic>a</italic> − <italic>a</italic><sub>0</sub>. The experiment data of NiO thin films were prepared at several deposition temperatures in the range of 380–460°C. All estimated values of crystallite sizes are proportional to the experimental data. Thus, the measurement of the crystallite size values by this proposed model is compatible with practical measurements qualitative.</p></sec></div>

The Deposition Temperature Dependence on the Crystallite Size of NiO Thin Films

Materials and Geoenvironment

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

{"article-title":"The Deposition Temperature Dependence on the Crystallite Size of NiO Thin Films"}

In this article, we have investigated a fitting proposal model for calculating the crystallite size of pure NiO thin films by varying the structural...

The Deposition Temperature Dependence on the Crystallite Size of NiO Thin Films

Article Category: Original scientific paper

Published Online: Jun 15, 2020

Page range: 35 - 38

Received: Jan 07, 2020

Accepted: Feb 11, 2020

DOI: https://doi.org/10.2478/rmzmag-2020-0001

Keywords
NiO thin films, deposition temperature, crystallite size, defect structure, fitting

© 2020 Said Benramache et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

The Deposition Temperature Dependence on the Crystallite Size of NiO Thin Films

Article Category: Original scientific paper

Published Online: Jun 15, 2020

Page range: 35 - 38

Received: Jan 07, 2020

Accepted: Feb 11, 2020

DOI: https://doi.org/10.2478/rmzmag-2020-0001

KeywordsNiO thin films, deposition temperature, crystallite size, defect structure, fitting

© 2020 Said Benramache et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
NiO thin films, deposition temperature, crystallite size, defect structure, fitting