This hymn is given in the Atharvana rahasyam which is a very powerful mantra shastra text, unfortunately not available in full but in parts in various manuscripts. This is one such hymn which is in praise of the sun god and is highly revered by the sauras. (The worshippers of sun god as the supreme god)
Three great beeja mantras and ashtakshari mahamantra (the eight syllable maha mantra of shriman Narayana) is embedded in this hymn which makes it even more powerful.
By reciting the hymn, the devotee attains good health, wealth, longevity, nutritious food and the grace of the sun god.
Yagyavalkya krta Surya Stotra from Vishnu Purana 
Surya Stavaraja From Samba Purana 
Surya Dvadashanama Stotra (Tamil Edition) 
Yagyavalkya Kruta Surya kavacham 
Surya Ashtakam by Samba from Samba Purana 
Rama Prokta Hanumat Kavacham 
Twelve Names of Manasa 
Vaidyanatha Ashtakam 
Renuka Kavacham 
Dvadashakshara Stotra From Brihad Dharma Purana 
Markandeya Krta Mrutyunjaya Stotram 
Ganapati Sahasranama Stotra Parayana Vidhi 
Lalita Pancharatnam 
Fourteen Names of Dattatreya