Open a PDF document to a new browser in the Document Library

If you want only documents in one document library to open to new windows, you can edit the document library in SharePoint Designer.

1.      Open the site in SharePoint Designer and then open the document library allitems.aspx.

2.      Right-click the document library web part and select “Convert to XSLT data view”.

3.      Locate the name column, you will see this tag “<xsl:otherwise ><A onfocus="OnLink(this)"  HREF="{@FileRef}"….. </xsl:otherwise>”, 

    add “target="_blank"” in <A> tag.

After this, the documents will be opened in a new window.

Hope it can help you.