Transparent substrate provided with a stack of thin layers, application to thermal insulation and/or solar control glazings

A transparent substrate having multiple thin layers, comprising successively:

• i) a first dielectric material layer;
• ii) a first layer having infrared reflection properties;
• iii) a second dielectric material layer;
• iv) a second layer having infrared reflection properties;
• v) a third dielectric material layer;
• wherein a thickness of said first layer having infrared reflection properties is 50 to 80% of that of said second layer having infrared reflection properties;
• wherein each of said layers having infrared reflection properties is surmounted by a thin, partly oxidized, barrier metal layer selected from the group consisting of tantalum and Ni—Cr alloy;
• and wherein at least one of said layers having infrared reflection properties is deposited on a thin metal layer selected from the group consisting of Ni—Cr alloy and tin.