**Author details**

*Electromagnetic Materials and Devices*

<sup>χ</sup> <sup>=</sup> \_\_\_\_ *<sup>C</sup> T* − θ

*3.3.7 O 1s XPS spectra*

adsorbed O2 [66, 67].

**Acknowledgements**

India.

**4. Conclusion**

nanoparticles, involve a Curie–Weiss behavior related with susceptibility (χ) as:

ture, and θ is the Weiss constant (in K) [10]. The estimated value of θ is found to

notable deviation from the Curie-Weiss law that might be attributed by short-range

In order to examined the presence of oxygen vacancies, VO, the O 1s XPS spectra of pure ZnO, Zn0.95Fe0.05O (ZFO5) and Zn0.92Fe0.05La0.03O (ZFLaO53) nanoparticles are given in **Figure 10** [47]. It deconvoluted into three peaks (Oa, Ob, Oc). The peak located on the low binding energy side (Oa) around 529.73 eV is attributed to O2<sup>−</sup> ions on the wurtzite structure. The Ob peak at about 530.65 eV is associated with O2<sup>−</sup> ions in oxygen-deficient regions within ZnO matrix, which indicate the formation of defects. The Oc peak at about 531.37 eV is usually attributed to chemisorbed oxygen on the nanostructural surface of the ZnO, such as adsorbed –CO3, H2O or

The ferromagnetism in multiferroic, DMS and ferrites is a topic of intensive research due to their superficial potential in spintronic and magnetic memory devices. The lattice defects related to these multiferroic, DMS and ferrites have an important role in mediating observed ferromagnetism. The lattice defects mainly are oxygen vacancies and their formation might be related with crystalline structure, heating condition during syntheses and types of nanostructural product.

This work is financially supported by Dr. D.S. Kothari Postdoctoral Fellowship (No.F.4-2/2006 (BSR)/PH/16-17/0066) under University Grants Commission,

be negative, which indicate antiferromagnetic interactions. But χ−<sup>1</sup>

ferromagnetism, antiferromagnetism, or a spin-glass system [65].

; where C is the material specific Curie constant, T is the absolute tempera-

(T) displays a

**110**

Kuldeep Chand Verma1 \*, Ashish Sharma1 , Navdeep Goyal1 and Ravinder Kumar Kotnala<sup>2</sup>

1 Department of Physics, Panjab University, Chandigarh, India

2 CSIR-National Physical Laboratory, New Delhi, India

\*Address all correspondence to: dkuldeep.physics@gmail.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
